Why I Can’t Be An Atheist

Almost a year ago I started posting about my exploration of what I see as the strongest arguments for and against the existence of God, and I started writing these posts several months earlier than that. Almost half of the posts on my blog so far have been directed at this question. (And on top of that, apparently my average word count per post has been higher this year than last!) So it has been a fairly long project.

Looking back over all of the thoughts I’ve gathered, here is where I find myself: I cannot be an atheist.

I can imagine why someone might be an atheist. I can imagine how you might weigh the considerations differently so that atheism is reasonable, even. But for me, that is not an option. For me, the arguments for God’s existence substantially outweigh those against.

What I Have to Believe to be an Atheist

Here is what I would have to believe in order to be an atheist:

  • The principle of sufficient reason is false, and the fact that the universe seems to work like it is true is just one huge coincidence. Abductive and inductive reasoning is invalid, and most of our scientific reasoning is undermined.
  • There is ultimately no reason why the universe (or anything at all) exists, or is the way that it is.
  • There is no explanation for the finely-tuned structure of the physical universe, except perhaps for vastly improbable chance.
  • The existence of consciousness is inexplicable, and in fact, because of this, the connection between our experiences and any external reality becomes dubious.
  • There is no such thing as objective morality, no right or wrong. Morals are just subjective impressions foisted upon us by our evolutionary and cultural history, and we have no fundamental obligation to follow them.
  • There is no such thing as objective beauty. Any sense of the transcendent we have in the sight of something beautiful; any experience of awe and wonder at the world around us; is empty and illusory.
  • There is even no such thing as objective rationality, and it is dubious whether our ways of reasoning, even deductively, are capable of reliably producing truth.
  • In a universe void of the transcendentals of truth, goodness, and beauty, with no teleology in our creation, living insignificant lives in the overall scheme of things, and universally destined for non-existence no matter what we do, life is ultimately without value, purpose, or meaning. (And we can pretend otherwise, but it doesn’t change the reality.)

In contrast, in exchange for the meaningfulness, explanatory coherence, and firm foundation that theism brings to one’s worldview, I only have to accept these tensions in order to be a theist:

  • I cannot fully understand why God would create a world containing evil and imperfection (though I can come up with some plausible reasons why he might do so, in general).
  • I cannot fully understand why God would not make more complete revelation of himself universally available, instead revealing himself in particular places and times in history and allowing many false religions and ideas about him to propagate (though again, I can come up with some plausible reasons why he might do so, in general).
  • I cannot fully understand how God has acted in regards to salvation, eternal life, and those who are excluded from that destiny (but logically, I see no barrier to things turning out in a way that accords with his goodness).

I could, perhaps, be accused of playing things up a little bit here for rhetorical effect. I am not saying that these conclusions are obvious and rationally compelling for everyone. I don’t think all atheists are inherently irrational. But at the end of the day, I do think they are mistaken. Under the light of the arguments for God’s existence, I find that atheism results in absurdity.

I admit haven’t spent as much time exploring and responding to the arguments against God’s existence on this blog as I would have liked to – there is much more that could be said (and has been said, elsewhere on the internet) regarding those subjects. And ideally, in a wrap-up post like this I would be including a quantitative assessment of the cumulative strengths of the reasons for and against belief in God, accounting for the degree of dependence or independence between the different arguments.

I will at least attempt to do that quantitative assessment, briefly, here. (“Briefly.” Ha.)

Quantifying Belief

In the comments on a post a few weeks back, one gentleman (who his own blog worthy of reading) suggested a high-level categorization of the arguments for and against God’s existence, and I think it is a good way of looking at things:

  • Argument from Reality: theism is the best way to explain some fundamental features of reality (encompassing the cosmological, teleological, noetic, and axiological arguments).
  • Argument from Imperfection: atheism better explains the fact that reality is full of imperfection (encompassing the problem of non-god objects, the problem of evil, and dysteleological arguments).
  • Argument from Revelation: theism is supported by experiences of God and the evidence of God’s actions in history (encompassing the epistemological and historical arguments).
  • Argument from Indifference: atheism better explains the apparent indifference of religious revelation (encompassing the problem of divine hiddenness, the problems of religious pluralism and religious disagreement, and the problem of exclusivity).

The argument from imperfection is paired against the argument from reality, and the argument from indifference is paired against the argument from revelation. (One further category, which I’m not going to consider in this analysis due to the difficulty of casting them as abductive arguments, would have the ontological argument on the side of theism, and contradictions in the concept of God on the side of atheism.)

Now what I want to do is run a Bayesian analysis of the odds for theism over atheism, considering each of these arguments in turn: reality (R1), imperfection (I1), revelation (R2), and indifference (I2). Using the odds-ratio form of Bayes’ theorem, and iterative use of the fact that P(A & B) = P(A|B)*P(B):

\frac{P(G|R1,I1,R2,I2)}{P(\sim G|R1,I1,R2,I2)}=\frac{P(I2|G,R1,I1,R2)}{P(I2|\sim G,R1,I1,R2)} \times \frac{P(R2|G,R1,I1)}{P(R2|\sim G,R1,I1)} \times \frac{P(I1|G,R1)}{P(I1|\sim G,R1)} \times \frac{P(R1|G)}{P(R1|\sim G)} \times \frac{P(G)}{P(\sim G)}

To make estimating these probabilities a more reasonable task, I am considering them all to be conditional on some level of background knowledge which frees us from having to consider the probabilities of many irrelevant specific contingent data about the world. In this way the focus can be on whether each worldview in consideration (theism or atheism) has the resources to explain the high-level facts we are interested in.

Even with that, it is hard to pin down some of these numbers, so I will actually model them as a distribution of probabilities. More on that below.


First, I think it is fair to consider the prior odds of theism (and atheism) to be one to one, or approximately so. I mentioned Paul Draper’s “low priors” argument a few posts ago, but as I said then, I don’t think it is successful. The intrinsically symmetric alternatives that he considers, “source physicalism” and “source idealism,” both need to be further specified to account for the full range of data. And I see no reason to think that theism must be further specified from source idealism than a viable form of atheism must be from source physicalism.

So P(G)/P(~G) = 1.


Now, does the existence of God provide a solid ground for the fundamental features of reality (e.g. existence, appearance of design, consciousness, objective value) that need to be explained? Without considering any of the imperfections in reality – that is the next argument, not this one – I would say the answer is a solid yes. So I will set P(R1|G) = 1.


The argument from reality is atheism’s weak point, in my mind. In order to explain these fundamental features of reality, it faces all the difficulties that I raised above. (And I’m trying to stick to the rational difficulties, but there are serious existential difficulties as well.) My initial impulse is to rate this probability no higher than 0.01, with 0.001 being closer to what I would put it at on most days. Just the failure of the PSR alone, I think, is worth putting it below 0.01.

That is probably a bit extreme, so I will ease off by a factor of 2 and say P(R1|~G) = 0.002 to 0.02. (Median value 0.006.)


Of the considerations that could go under the argument from imperfection, I have only specifically addressed the problem of evil on this blog. But the others, the problem of non-god objects (why would God, a perfect being, create anything at all?) and dysteleological arguments (why would God create things that appear poorly designed?) do not add much weight to it, honestly. And given what I think are good responses to the problem of evil, I don’t think this probability needs to be much lower than 0.5.

But recognizing that the argument from imperfection does cause some tension for theism, I will estimate P(I1|G) = 0.1 to 0.4. (Median value 0.21.)


Assuming atheism could overcome the argument from reality, can it explain all the imperfections and evils that we see? Yes, completely. P(I1|~G) = 1.


The question here is whether it makes sense for God to provide some revelation of himself and whether theism can account for the kind of examples of revelation that we see. I think the answer is yes, in general, and that this probability is pretty close to 1. To make things simpler, any doubt about this can be transferred to a boost to the next probability. So P(R2|G) = 1.


For me, this probability would be pretty close to 1 (making the argument from revelation quite weak) if it were not for the events surrounding Jesus’ death and the origin of Christianity. I do think atheism has difficulty explaining the evidence that we have for what happened there.

Nevertheless, assessing the argument for the resurrection is a complicated matter, and I am fairly uncertain about just how much force it has. My initial thought is to put this probability anywhere from 0.01 to 0.5. To offset the value of 1 given to the corresponding probability on theism, I will set P(R2|~G) = 0.05 to 0.6. (Median value 0.22.)

(*Note: in an earlier version of this post, I instead set P(R2|~G) at 0.15 to 0.75, wanting to be generous to the other side. But upon later reflection, I felt this really underrepresented my assessment of the strength of the evidence, even taking my uncertainty about that into account. With the original numbers, the median value for my overall probability for God’s existence was about 91.5% instead of 95.3%.)


The question that theism has to face now is why God’s revelation of himself is apparently so ineffective and localized. Why would God not make his existence more obvious? Why is there so much religious confusion? How could God leave people in this state of uncertainty, and then condemn them to hell?

The kinds of considerations that I have raised in response to these things in that past few posts go a ways to reducing the tension that the argument from indifference brings to theism – but I find it more difficult to overcome than the argument from imperfection. Let us say that P(I2|G) = 0.05 to 0.3. (Median value 0.13.)


Finally, can atheism explain the apparent indifference of religious revelation? Again, it can do so perfectly. P(I2|~G) = 1.

For each of the four probabilities with a range of values, I have modelled them using a logit-normal distribution with the upper and lower values listed above set to the 10th and 90th percentiles. These are what the distributions look like:


subjective distributions

And once these random values are put into the Bayesian equation, and the result converted into a distribution for the posterior probability that God exists (using 10,000 sets of randomly generated numbers to estimate the distribution), this is what I end up with:

subjective distribution output smoothed

This ranges from 82% at the 10th percentile to 98.8% at the 90th percentile, with a median probability of 95.3%. (An equal probability for theism and atheism, at 50%, is down below the 1st percentile in this distribution.)

So, there you have it. Given how I’ve weighted the above arguments, I should on average be a bit more than 95% confident that God exists.

Faith and Reason

This value (or distribution of values) represents an assessment of the strength of the rational justification for belief in God. Obviously, it is a product of several subjective judgements, and different people could weight the arguments differently and get a different number out as a result. On a different day, I myself might feel that different numbers are more appropriate than the ones I have given here. So this number shouldn’t really be thought of as any kind of precise determination of my level of belief in God.

But even more than that, while rationality is extremely important, at the end of the day I have to admit that it isn’t the only consideration that goes into forming one’s beliefs. There are existential considerations as well: considerations about finding meaning and purpose in our lives, and about how our beliefs are going to impact the way we live. So while I definitely think that there are good reasons to believe in God – 95% isn’t insignificant, after all – there is more than that. And the meaning and purpose of life that I find in the theistic worldview draws me, essentially, to commit to what I see as the truth.

The existence of God is too important, and the implications too far-reaching, for it to be practical to be indefinitely weighting the reasons for and against theism, holding that left tail of the distribution in mind and wondering if it will change. This gets back to something I wrote about at the very beginning of my blog: we need critical thinking, but we also need epistemic faith. When we see good reasons to accept a belief – as I see good reasons to believe in God – we should trust that, and not linger in unnecessary skepticism.

Basically, what I am saying is that I am willing to take that last 5% on faith, and I think it is proper to do so. I will trust what I have good reason to believe.

This does not mean that I think I should seal up the issue of belief in God and never subject it to scrutiny again. If something comes up that makes me think about how I’ve weighed the evidence, or if I come across some new consideration that could affect the balance, I am willing to take a look at it. (Granted, given the scope of my exploration of this issue so far, I admit that I find it unlikely that something will ever impact my belief so much as to make me change my mind. But I want those who disagree with me to be open to changing their mind, so I should probably exhibit the same attitude!)

So, that is why I am not an atheist. In my next post, I will write a little bit more on why I believe that Christianity, specifically, is true.

The Problem of Divine Hiddenness

In this blog I have surveyed what I believe to be seven (or so, depending on how you count them) fairly strong arguments for the existence of God. But it is nonetheless true that God’s existence is not completely obvious to most people in the way that, say, the existence of the physical world is obvious. So why is the evidence for God’s existence not more direct? Why doesn’t God make his presence as clear as day to everyone – especially when he supposedly wants people to know him?

This is the problem of divine hiddenness, also called the argument from non-belief, and to me it is one of the two strongest arguments for atheism (together with the problem of evil, which I will discuss in the next post). It can be formulated simply as follows:

  • If God exists, then he is perfectly loving.
  • If God is perfectly loving, he would make it so that every person believes that he exists.
  • Some persons do not believe that God exists.
  • Therefore, God does not exist.

The gist of the argument is that, if God existed, he would want to be in a loving relationship with every person he created. But a precondition for being in a loving relationship with God is believing that God exists. So, God would ensure that everyone is aware of his existence in order for it to be at least possible for them to enter into a relationship with him.

Since in fact it does not appear to be the case that everyone is aware of God’s existence, this line of reasoning lends support to the belief that God does not exist.

Evaluating the Argument

As a theist who finds the axiological and ontological arguments for God compelling, I am in complete agreement with the first premise: if God exists, then he is perfectly loving. So we can take that as a given.

The third premise, I believe, is also fairly obviously true. There are Christians who claim (on the basis of a couple verses in the Bible) that deep down, everyone really believes that God exists: no one is truly an atheist, and anyone who claims they are is lying, even to themselves. I have come to think that this is a very mistaken response. It is extremely uncharitable, it actually isn’t well supported by Scripture, and it isn’t well supported by the testimony of many current and former non-theists. See this article by Randal Rauser for more on that. So I also accept the premise that there are real atheists and agnostics out there.

The second premise is more questionable. Here is how it might be justified. Since God is perfectly loving, he desires the best for everyone. Since God is the locus of all value, being in a personal, loving relationship with God is the greatest good that anyone can experience. So God desires for everyone to be in a right relationship with him. And more simply, since he loves everyone, he desires relationship with them for its own sake: and he would certainly reach out to them rather than abandoning them to an existence devoid of the goodness of his presence.

Now, if belief in God is indeed a precondition for right relationship with him, then we can make the inference from “God desires for everyone to be in a right relationship with him” to “God desires for everyone to believe that he exists”. And I think it is certainly the case that, for the kind of deep and reciprocal relationship that God ultimately desires us to have, belief is required. However:

  • Not all persons may be capable of belief in God. (For example, infants or cognitively impaired persons.) Nevertheless, it may be that such persons can still have a kind of relationship with God, the way that even an unborn child has a kind of relationship with her mother.
  • Since God is not just one personal being among others, but is also the ground and locus of all value, it may be possible to have a positive relationship with God even without believing in him, by relating to Goodness, Truth, and Beauty.
  • If God has foreknowledge of our free choices, he knows whether producing belief would lead to the kind of positive relationship that he is interested in. There may be those who, upon coming to believe that God exists, would still reject relationship with him, enter into an improper relationship with him, or enter into a relationship with him which they would ultimately choose to forsake. (Such persons may or may not be culpable for being in these contrary states; there can be a variety of reasons for such dispositions.) God’s reasons for producing belief in these cases are much reduced.
  • Similar to the above point, there may be people to whom God has given sufficient rational grounds for belief in his existence, who have freely and culpably rejected those grounds, or who have shut themselves off from God in some other way (for example, by refusing to seek God because of a desire to be in control of their own life). Not desiring a coerced relationship, God’s reasons for forcing belief on such persons are also reduced.

This means there is some reason to doubt that God’s desire for relationship automatically leads to God’s desire to produce belief in his existence. Furthermore, even if God desires for someone to believe that he exists, that does not imply that he has an all-things-considered desire for that person to believe that he exists. God may have other considerations, some in favour of allowing created persons to remain unaware of his existence, at least for a time. Here are some reasons for divine hiddenness:

  • Delaying in making evidence available for a person to believe in God may alter their circumstances in such a way that they enter into a higher quality relationship with him later than they would have if he had made such evidence available earlier. (Daniel Howard-Snyder argues along these lines in this paper.)
  • Divine hiddenness may allow for greater independence and interdependence of creatures, benefiting our moral development. (Dustin Crummett makes this suggestion here.)
  • Divine hiddenness may reduce coercion in some situations and allow for more opportunity to freely choose what is good for the right reasons (i.e. because it is good, not just for fear of punishment, for example).
  • Perhaps it is appropriate to God’s holiness to maintain a certain degree of distance from his creatures.
  • Because of the butterfly effect, divine hiddenness could lead to better possible outcomes in ways that are totally unpredictable from a human perspective, but that can be foreseen by an all-knowing God.

(Take a look here for a resource that explores some of these possibilities further, with references to other philosophical works.)

In evaluating why God may remain hidden from some people, we also have to consider that if God exists, then human persons may have an eternity before them in which to relate to God: our mortal lives may just be an infinitesimal sliver of the whole of our existence. Which means that for all we know, God’s sacrificing some depth of relationship for a short time in order to obtain other goods may very well be justified.


Given these considerations, I am far from certain that the second premise of the problem of divine hiddenness can be sufficiently supported. Perhaps we could modify it:

  • If God is perfectly loving, then for every person A who is capable of entering into a personal relationship with God, such that A has not culpably shut themselves off from relationship with God in some way, God brings it about that A believes in his existence, unless he has an overriding reason to permit A to remain in non-belief.

I can accept this premise with reasonable certainty. But then we need to modify the third premise in order for the argument to remain valid:

  • There is at least one person who has not culpably shut themselves off from relationship with God, and who has not come to believe in God’s existence; and God has no overriding reason to allow this person to remain in unbelief.

And this premise is quite plausibly false. At the very least, it seems impossible to prove from a human perspective: we cannot possibly be in a position to adequately evaluate all of God’s reasons for doing something, and we can think of a few reasons in favour of divine hiddenness that cannot be ruled out conclusively.

(Note: There is, perhaps, one very important consideration which the proponent of the hiddenness argument could raise to say that God cannot have an overriding reason to allow anyone to indefinitely remain in unbelief: the person’s eternal salvation depending on having a right relationship with God. This gets into the problems of religious pluralism and exclusivity, which I will discuss in upcoming posts.)

Thus, I think it is quite reasonable to disbelieve this modified premise (provided the theist has a response to the problems of religious pluralism and exclusivity). Which means that, while the problem of divine hiddenness introduces some tension into a theistic worldview, in the end I do not find that tension to be insurmountable. After all, there is evidence for God’s existence, so he is not and does not remain completely hidden. And it may very well be that this evidence is enough to accomplish God’s purposes in this world: enough for people to seek him and begin a loving relationship with him, if they so choose.

Obviously, I have only scratched the surface of this topic, and there is a great deal of philosophical work that has been done (and that is still being done) to explore it further. I have to admit that in this post I haven’t dealt with the problem of divine hiddenness in as much depth as I’d like. In the future, I may come back to expand on what I’ve written here. For now, I want to keep moving on to new topics (and I don’t have as much time for blogging these days), so I am content with this overview.

The Presumption of Atheism

Do we really need a reason to not believe in God? Isn’t atheism the default position?

To answer this question we need to distinguish between believing that God does not exist on one hand, and not believing that God exists on the other. The former is the belief in an absence. The latter is simply the absence of a belief.

“Atheism” is commonly defined as the belief that God does not exist, but there are a growing number of people who define it in a weaker sense as the state of not believing that God exists (beginning with Antony Flew, who first suggested to use “atheism” in this way). For clarity, I will call the former sense “positive atheism” and the latter sense “negative atheism”.

So then, is atheism the default position? The answer depends on whether you mean positive or negative atheism.

If you mean negative atheism, then yes! I am in complete agreement that negative atheism is the default epistemic state. One does not need arguments or evidence to be a negative atheist, because negative atheism isn’t a belief at all. Being merely the lack of a belief, it does not assert that anything is true, and so requires no justification. It is just a description of someone’s subjective mental state. Babies, cats, and rocks are all negative atheists, since they do not hold a belief in the existence of God. (At least, we don’t think they do.) Positive atheists are negative atheists, but the converse isn’t necessarily true – agnostics are also negative atheists. (Which is why, if you want to distinguish between atheism and agnosticism, you have to mean positive atheism.)

Negative atheism is trivial. Note that we can just as well define “negative theism” to mean not believing that God does not exist, and then that is also the default position! (Someone can lack both the belief that God exists and the belief that God does not exist, and indeed the babies, cats, and rocks of the last paragraph are in that position – along with the agnostics.)

Because “negative atheism” is so trivial, it is only a useful category in some sociological contexts – in studying the kind of things that people believe, for example. But when we are talking about more than that – when we are talking about whether or not God really exists, not just what people believe about that – what we care about is “positive atheism”.

And there, the situation is quite different. If you claim that positive (not merely negative) atheism is the default position, well, you are simply wrong. Positive atheism is a belief – it takes a stand and asserts that something is true (namely, that God does not exist). And we should have reasons for believing what we do. We should seek to have justified beliefs. Thus, positive atheism requires justification to back up the assertion that it makes, which means it is not the default position.

I think this is worth repeating. The claim that God does not exist is no less strong of an assertion about the nature of reality than the claim that he does. So atheism (that is, positive atheism) is not an epistemically neutral stance. In order to be an atheist in any philosophically significant sense of the word, you have to have reasons.

To put a bit more rhetoric behind this statement: the atheist who says that he needs no evidence for atheism (because it is the “default”) is no better than the fideist who says that he needs no evidence for theism (because he accepts it by “faith”). Worse, even: at least the fideist usually recognizes that his position is irrational.

You’ll find atheists who say that atheism is not a claim, and therefore it has no burden of proof. But this can only be true of negative atheism: if said about positive atheism, it is blatantly false. The distinction between theism and atheism is not that one claims something and the other doesn’t. Rather, the distinction is that one is a positive existential claim (it claims that something exists) and the other is a negative existential claim (it claims that something does not exist).

And there is nothing about negative existential claims which makes them exceptions to the rule that we should have rational justification for what we believe. For comparison: philosophical idealism makes a negative existential claim, but that does not make it the default position, nor does it allow us to deny the reality of the physical world without valid reasons.

Reasons for Atheism

The saying “you can’t prove a negative” becomes relevant here. Some people assume that this is true, and that it means that justification for a negative existential claim can’t actually be given, letting atheism off the hook. But this saying is false. There are perfectly good ways to justify negative existential claims. There are, in fact, some reasons to believe atheism. Therefore, the requirement that atheists have reasons to be atheists is not unreasonable.

First, though, here are a few statements that are not reasons to be an atheist:

  • “There isn’t any evidence for God.”

If by “evidence” you mean the kind of natural, physical evidences that we study with science, then you’re looking in the wrong place. It presupposes atheism or philosophical materialism to insist that all justification for beliefs has to be evidence of this kind. Moreover, it is self-refuting, since we rely on certain non-evidential beliefs in order to acquire and use evidence at all. Construing “evidence” more broadly to mean any rational justification for a belief, this objection is false. See: all my previous posts on arguments for God’s existence.

  • “None of the arguments for God’s existence are convincing.”

This leaves you without a reason to believe that God exists, but it doesn’t give any reason to believe that he doesn’t. So at best, this leaves you with agnosticism. If you say you can be an atheist merely because you haven’t been convinced about theism, then you might as well say you can believe anything you want as long as it is not obviously false. I think rational belief requires a little bit more than that.

  • “God isn’t a valid explanation of anything.”

This objection is sometimes used against the cosmological or teleological arguments, saying that the God hypothesis is really a non-explanation. But for one, this objection is false: if God exists and created the universe, then God obviously would be an explanation for the existence of the universe. (And so the claim that God is a non-explanation just presupposes atheism, without justification.) And for two, even if true, this objection would only negate reasons for theism, rather than providing reasons for atheism.

(See also here for a further exploration of the not-a-valid-explanation objection.)

  • “Science shows that God doesn’t exist.” Or, “Science shows that we don’t need to posit God to explain anything.”

No, it doesn’t. I’ve written about this before. But by way of brief response: science allows us to explain a lot of things via natural causes, but it cannot explain everything, and it certainly cannot explain where those natural causes themselves come from. (To take up that question is to leave the realm of empirical science and go deep into the realm of philosophy.)

With those out of the way, here is one statement that is a valid reason to be an atheist (if true):

  • “There isn’t enough evidence for God’s existence, compared to the amount that there would be if he did exist.”

Absence of evidence is not evidence of absence, as the saying goes – unless we should have that evidence if the thing did in fact exist. (For a more in-depth exploration of that principle, see here.) Where this is used as an argument for atheism, it is known as the problem of divine hiddenness. More generally, we can provide justification for negative existential claims in the following way:

  • “If X exists, then Y should be true. But Y is false. Therefore, X does not exist.”

This is the logical form behind the problem of evil and other arguments against God’s existence. These are the kind of arguments that can actually justify atheism, and they are what I will be exploring in upcoming posts.

Implausibility of Theism

There is one further argument that I will address which is relevant to the question of whether or not atheism can be considered the default epistemic position. It is raised by Paul Draper in his article on atheism and agnosticism in the Stanford Encyclopedia of Philosophy. The idea behind this “low priors” argument is that theism is intrinsically improbable, so that even before taking any evidence into account, the presumption is in favour of atheism.

Draper argues for the low prior probability of omni-theism (his term for the kind of theism that I believe follows from the arguments for natural theology) by comparing it to an alternative position that he calls source physicalism:

  • Source physicalism: the physical world is ontologically ultimate, and any mental reality depends on the physical for its existence.
  • Source idealism: the mental world is ontologically ultimate, and physical reality depends on the mental for its existence.
  • Omni-theism: a subset of source idealism, which further specifies the ontological ultimate to be a unique, perfect person.

Draper’s claim is that 1) source physicalism and source idealism have equal intrinsic probabilities, principally because of the symmetry between the two positions, and 2) omni-theism is a very specific version of source idealism and therefore it must be much less intrinsically probable than source idealism in general. From this it follows that 3) omni-theism is much less intrinsically probable than source physicalism.

These claims are, of course, contestable. Despite Draper’s assertion, there is an asymmetry between source physicalism and source idealism, both in regards to our epistemic position (we can doubt the existence of the physical world, but we cannot rationally doubt the existence of our own minds), and in regards to their ontological status (there are mental phenomena that do not seem possible to derive from the physical world even in principle). It seems to me that these are a priori considerations that could tip the balance in favour of source idealism in terms of its intrinsic probability, over source physicalism.

Second, it seems to me that Draper’s claim about the specificity of omni-theism, compared to source idealism, is greatly exaggerated. Over and above source idealism, omni-theism simply claims that the ontological ultimate is personal instead of impersonal, one instead of many, and perfect instead of imperfect. The first of these additional claims arguably has the advantage due to similar considerations as those in the last paragraph. And the latter two claims are in some sense simpler than their counterparts, and could claim greater intrinsic probability on that basis.

Finally, omni-theism is actually a very simple hypothesis: it postulates the existence of a single entity (an immaterial person) who can be described by perhaps just three properties (knowledge, power, and goodness) and who possesses those properties in the simplest possible way (to the maximum degree, with no limitations). Compare this to Draper’s source physicalism, which has to postulate the brute existence of a number of physical entities, laws, constants, and initial conditions (or some kind of mechanism for generating such). So I would say that considerations of simplicity actually tip the balance of intrinsic probability in favour of theism!

So I don’t believe that Draper is successful in his argument that omni-theism is many times less probable, intrinsically, than source physicalism. Which means that is not a good reason to take atheism as the “default position”.


An aside on Draper’s arguments in the article referenced above:

I might add that Draper’s complete “low priors” argument also includes the premise that the total evidence does not favour omni-theism over source physicalism. (Where “evidence” in this context means any rational source of justification for a belief – experience, arguments, etc.) Combining this with the premise that omni-theism is intrinsically much less probable than source physicalism, he concludes that omni-theism is very probably false, and thus, atheism (understood just as the denial of omni-theism) is very probably true.

As I said, I think there is reason to doubt the premise about the intrinsic probabilities of omni-theism and source physicalism. But even if that were established, I absolutely disagree with this claim about the balance of the evidence. Justifying it requires one to undercut or defeat all of the arguments for omni-theism from natural theology, or at least to balance them with equally strong arguments for source physicalism. And that, from my perspective, is a very difficult task.

(Draper’s appeal to the “fallacy of understated evidence” is a good starting point for discussion about potential weaknesses or balancing considerations of certain theistic arguments, but it in no way shows that those considerations actually succeed in reducing the force of those arguments by a significant degree.)

Interestingly, the failure of this premise is related in a way to the potential success of the other one. One of the ways that Draper tries to justify his premise about the intrinsic improbability of omni-theism is by saying that omni-theism makes very specific claims, each of which must reduce its probability. But if we’re being rational, we theists don’t just make those claims out of the blue. We make specific claims about God and reality because of reasons that we see for them (for example, from natural theology). So in the end, theism’s level of intrinsic probability doesn’t really matter. The important thing is its probability when the evidence is taken into account.

The put it another way, omni-theism is not postulated a priori as an arbitrary refinement of source idealism, any more than the Standard Model of particle physics is postulated a priori as a refinement of source physicalism. These things are postulated as hypotheses to account for facts that need to be explained. So the fact that omni-theism is more specific than source idealism is no more of a strike against theism, to my mind, than is the fact that the Standard Model is more specific than source physicalism a strike against atheism.

One more note: Draper has a second argument for atheism in that article, his “decisive evidence” argument. This one isn’t really a distinct argument, since its premises basically assert that 1) none of the argument for theism are successful, and 2) there is an argument for atheism that is successful. (There’s more nuance to it than that, but when you really break it down the premises are justified only if those two things are true.)

End aside.


So far, I’ve explored two reasons that are often put forward for rejecting theism in favour of atheism: arguments that theism is impossible, and the presumption of atheism as the default epistemic position. And in my honest evaluation, neither of these carry any rational weight whatsoever.

In the next few weeks I will explore some atheistic arguments that I think do have force.

The Epistemological Argument (III)

My last two posts have been about what I call the epistemological argument for belief in God, also known as the argument from religious experience. So far, I have defended the claims that:

  1. The principle of critical trust is valid and applies to religious experiences,
  2. religious experiences occur, and
  3. a certain type of religious experience, theistic experience, is well-established.

Now if:

  1. overriding reasons to doubt theistic experiences are not present,

it will follow that:

  1. we are justified in believing in God on the basis of theistic experiences.

This is just because of what the principle of critical trust says: if a type of experience is well established and an experience of that type is not defeated by other reasons, it is rational to believe it. I have also argued that testimony is a valid source of justification for beliefs, so if these premises are true, we are also justified in believing in God on the basis of the theistic experiences of others.

Defeaters of Theistic Experiences are Not Successful

The final premise that I have to defend is that, in many cases of theistic experiences, there are no overriding reasons to disbelieve them, so that their inherent justification (which is sufficient to accept them as true, since they are a well-justified type) is not defeated.

Note that it doesn’t need to be the case that every theistic experience remains undefeated in order for such experiences to provide evidence for the existence of God. If some experiences are invalidated, that does not necessarily transfer to the rest – just like a few instances of hallucinations do not invalidate all of our physical perceptions. Given that our senses and cognitive faculties are fallible, it would be surprising if there weren’t a few theistic experiences that should be disbelieved. But that doesn’t mean that we should disbelieve all of them.

Naturalistic Explanations

There are, I think, two potential reasons that we should disbelieve experiences of God. The first is if theistic experiences can be given naturalistic explanations – that is, explanations entirely in terms of the natural world, without invoking any kind of transcendent reality. If that were the case, it could undermine the justification they provide for belief in God.

For naturalistic explanations to be successful in defeating theistic experiences, they need to specify a set of natural causes sufficient to produce the experience, and we have to have reasons to believe that those causes render the experience false, or at least show that it lacks justification. Furthermore, we have to have reasons to believe that such sufficient causes are actually present in the majority of cases in order to write off all theistic experiences.

Are these conditions actually satisfied? I don’t think they are. At the very least, if they are, a whole lot more work needs to be done to show that they are. Those who dismiss experiences of God on the basis of naturalistic explanations have not provided enough justification for their dismissal.

Naturalistic explanations for religious experiences are generally psychological or neurophysiological. On the psychological side, people have often claimed that religious experiences are just the result of unconscious wish-fulfillment, defence mechanisms, or repression – explanations much in the style of Freudian psychoanalysis. But that kind of psychoanalysis is highly questionable. Notable philosophers of science like Karl Popper have placed it alongside astrology as non-falsifiable pseudoscience, resting more on ideology than evidence.

(Or there is the commonly-touted idea that religious belief is just the result of self-perpetuating indoctrination. Here is a blog post that explains the failings of that theory.)

Other psychological explanations include the suggestions that religious beliefs are formed because of a hyperactive agency-detection mechanism in our cognitive faculties, or that religious experiences are just the result of something like a psychosis. Other people have dealt with these kind of claims in more detail, but it seems to me that they don’t really succeed at providing a sufficient explanation for the broad range of theistic experiences – and little to no actual evidence has been put forward supporting them.

On the neurophysiological side, there is some evidence that certain drugs can induce, or at least increase the likelihood and intensity of, certain mystical experiences. It should be noted that, at most, all this really shows that mystical experiences can be faked; it does not demonstrate that non-drug-induced mystical experiences are unveridical. Physical sense perceptions can be faked as well, and this does not damage our justification for believing the majority of what we perceive.

In fact, even if it could be shown that certain brain states were correlated with religious experiences, it does not seem that this would mean that all religious experiences were false. Physical sense perceptions are correlated with certain brain states as well; this does not mean that the objects we perceive through them are illusions.

This counterargument can be taken further. Even if the brain states correlated with religious experiences could be shown to have a sufficient set of physical causes, it still would not conclusively demonstrate that those religious experiences were false, absent a solution to the mind-body problem: the correspondence between the mind and body could be such that certain brain states produce a real experience of transcendent reality by the mind. Since, I believe, a purely physical solution to the mind-body problem is not possible even in principle, the weight of the evidence from neurophysiological explanations is not very strong.

Conflicting Claims

The second possible reason to disbelieve experiences of God is that they present conflicting claims. It is evident that, if taken at face value, religious experiences from different traditions vary widely and present mutually contradictory stories of reality. Critics say this demonstrates that religious experiences cannot be reliable, and so in the end we cannot trust any of the beliefs that are formed through them.

First, note that the fact that there are conflicts between religious experiences does not mean that the principle of critical trust does not apply to them. A group of eyewitness accounts of an event will often contain conflicting claims, especially if the conditions for observing the event were not ideal. (For example, it was dark outside, the event occurred very quickly, etc.) But it would be irrational to reject all those accounts simply because they conflict. Rather, often you would start by finding where all or most of the accounts agree, and then you may try to reconstruct what actually happened by finding the best explanation for all the accounts. Of course, it may turn out that some of the accounts were more accurate than others.

This process of putting initial trust in conflicting accounts, and then subjecting them to critical examination, happens all the time in courts of law and in the study of history, to give two examples. This is just the principle of critical trust in action, and the same general process is applicable to religious experiences as well.

Second, the fact that religious experiences contradict each other does not mean that religious experiences are completely and totally unreliable: at most, it only means they are not as reliable as other types of experience. While there may be conflicts at the most detailed level of description, at a less detailed level there can still be agreement, a common core of claims shared by all or most experiences. The principle of critical trust implies that we preserve as much of the content of our experiences that is not defeated, so the common core is retained.

This is especially true when considering just the theistic experiences, which are a well-established sub-type of religious experience and so can be considered on their own merits. Here there is an even stronger common core, and if it can be shown that there is a plausible way to resolve any conflicts between theistic and non-theistic religious experiences, then we have good reason to trust at least the common core of theistic experiences. This would get us to the belief that God exists, along with a general concept of his being and character.

Third, even when a type of experience is relatively unreliable, some experiences of that type may still be accurate, producing true beliefs. So if a particular experience is coherent with and supported by a comprehensive worldview, one that best explains the majority of the evidence, it is still justifiable to trust that experience even if it is conflicted by others.

This can be illustrated by again considering the example of a conflicting group of eyewitnesses. If you are one of the eyewitnesses, and your experience of the event in question was clear, it seems to me that you would be justified in maintaining trust in your own experience even if other eyewitnesses give accounts that conflict with yours. This is especially true if some of the other accounts supported rather than contradicted yours, and there was a reasonable explanation for the contradictory accounts.

With all that being said, it seems to me the view that most plausibly resolves the conflicts between all the disparate religious experiences of mankind is the view that God exists. If God exists – if the Ultimate Reality is a Someone, perfect in power, wisdom, and holiness, rather than merely a Something – this readily accounts for all forms of theistic experiences, experiences of transcendence, and at least some lesser experiences of immaterial reality. (I am using here the terminology from my classification of religious experiences in the previous post.)

Conflicting claims about the identity of God as revealed in these experiences can be accounted for by recognizing that our experiences are generally fallible, and may be incomplete or misinterpreted. This is especially true if your worldview gives you reason to think that our spiritual senses are not functioning as they should in some respects. Some of the other encounters with immaterial reality do not cohere very well with a theistic worldview – encounters with minor deities such as Apollo, for example – but these are much less well-attested than theistic experiences, and they can be explained as the result of deception, delusion, or misinterpretation.

Nature mysticism is not out of place in a theistic worldview, either, since we are so integrated with our bodies and our bodies are intricately interwoven with the rest of physical reality. Moreover, we are united with the rest of the universe by being radically dependent on God for our existence. Pure consciousness events (if they are coherent) do not contradict theism, simply because they have no intentional content whatsoever. (Though some people believe that pure consciousness events are actually direct experiences of the immaterial self.)

That leaves monistic mystical experiences and experiences of Nirvana as the only kinds of religious experience that actually conflict with the existence of God. If taken at face value, they imply that the ultimate reality is impersonal, rather than personal. Notice however, that if he exists, God could easily manifest himself impersonally: this would just be an incomplete revelation where his personal nature is hidden. But on the other hand, an impersonal reality cannot manifest personally: such an experience could be nothing more than an illusion.

Indeed, in the monistic worldview everything is an illusion, since if the monistic mystical experiences are taken at face value, All is One and all the divisions between the different things we perceive are unreal. Such a worldview demands that we reject the vast majority of our experiences as false: not only theistic experiences, but experiences of the diverse and changing physical world, interpersonal experiences, and moral experiences as well.

The rejection of most of our experiences in order to preserve a minority of them is not recommended by the principle of critical trust. Because of this, I think it is far more reasonable to interpret monistic mysticism and experiences of Nirvana either (i) as experiences of impersonal aspects of God, such as his existence or that the existence of everything else is dependent on him, or (ii) as direct experiences of one’s own soul, or (iii) as misinterpretations of pure consciousness events or nature mysticism; rather than interpreting all theistic experiences to be false in light of these monistic experiences.


In summary, then, neither naturalistic explanations for theistic experiences, nor conflicts in some of their content, are really sufficient to override the inherent justification that we have to believe those experiences. These considerations may give us reason to doubt religious experiences in some cases, and to recognize that they may not be completely reliable. But it would actually be unreasonable to completely reject these experiences of God without further evidence against them – just as it would be unreasonable to completely reject unreliable eyewitness testimonies or conflicting historical accounts, instead of gleaning from them what truth we can.

This concludes my defense of the epistemological argument for belief in God. Experiences of God provide sufficient justification to believe in him. This is especially true for those who have such experiences – but given that they are a fairly widespread phenomenon, and that they cohere with each other on at least a general level, I think they reasonably count as evidence towards God’s existence even for those who do not have them.

In my next post, I will begin looking at cosmological arguments for God’s existence – arguments from the existence and origin of the universe itself.

The Epistemological Argument (II)

In my last post I began writing about the epistemological argument for belief in God, also known as the argument from religious experience. And I argued, from considerations of impartiality, that the principle of critical trust is applicable to religious experiences as it is applicable to any of our experiences, which is the first premise of the argument.

This means the beliefs that people form in the context of religious experiences have some degree of inherent justification – though perhaps not enough to warrant accepting those beliefs without corroboration and further critical examination. That is where the third and fourth premises come in, which are that a certain class of religious experiences are well-corroborated, and that overriding reasons to disbelieve those experiences are not present. Those are the premises I will defend in this post and the next.

Religious Experiences

Before I get into that, it is worth saying something about the second premise. People have religious experiences, experiences that they take to imply some kind of transcendent reality. This statement should be fairly uncontroversial, unless you want to make the rather audacious assertion that everyone who has ever claimed to have a religious experience is lying.

To get a sense of the diversity of human religious experience, here are some of the different kinds of such experiences that many people have reported. (This list is mostly taken from Kai-man Kwan’s article on the argument from religious experience, and some sources can be found there.)

  • Theistic experiences – experiences of God, the personal and perfect creator of the world
    • Numinous experiences – experience of God as a tremendously powerful being, a mysterious and awesome reality who is brimming with life and energy
    • Theistic mysticism – experience of deep unity of oneself with God, where the soul seems to experience God from within God himself
    • Sense of presence of God – awareness of the presence of God, often accompanied by a feeling of calm assurance and peace
    • Divine-human encounters – awareness of God’s ultimate worth as well as one’s own moral obligations to God, experienced along with feelings of personal interaction (warmth and gratitude, sense of being personally addressed)
    • Experiences of grace – feeling of being forgiven of one’s moral transgressions against God and being reconciled to God, feeling of peace and joy, freedom from guilt
    • Conversion and experiences of personal growth – feeling of being transformed by God, accompanied by moral character growth
    • Charismatic experiences – speaking in tongues, prophesy, faith healings, and the like
    • Sensory theistic experiences – visions, dreams, and the like
    • Corporate theistic experiences – experiences of God in corporate worship or prayer, or as an integral part of (religious) community life
    • Mediated theistic experiences – experiences of God mediated by other experiences, for example, in nature, art, conscience, fellowship with others, or moral character of others
    • Interpretive theistic experiences – spontaneous interpretation of an event as being from God, for example, feeling that an event is an answer to prayer or a sign from God
    • Intuitive apprehension of God – intuitive belief that God exists without any other experiential content
  • Experiences of transcendence
    • Experiences of contingency – profound feeling that this world is not ultimate and that it depends on something beyond
    • Experiences of design – profound feeling that the beauty and intricacy of the natural order is ultimately due to a creator
    • Experiences of ecstasy – feeling of ecstasy through encountering some kind of transcendent reality
  • Encounters with immaterial reality
    • Near-death experiences – out-of-body experiences or encounters with a transcendent reality when near death
    • Experiences of minor deities, evil spirits, angels, or departed saints – these differ from theistic experiences in that the being encountered is a finite part of reality, rather than transcending all other reality and sustaining it in being
  • Various mystical experiences
    • Nature mysticism – feeling of being one with the universe
    • Monistic mysticism – feeling that All is One, often with the belief that ultimate reality is impersonal, may include a pure consciousness event as part of the experience
    • Pure consciousness event – a state of pure consciousness with no intentional object or conceptual interpretation whatsoever
    • Experiences of Nirvana – feeling that No-self or Nothingness is the ultimate reality

Obviously, we cannot take all of humanity’s religious experiences at face value – many of them contradict one another, and it is very likely that some of these experiences will be found to be fraudulent or delusory even if God does exist. The same, after all, is true of our physical perceptions. Eyewitness accounts of the same event can contradict each other, and people can lie, hallucinate, or be fooled into thinking they saw something that they didn’t. (Of course, this can be used as an objection against believing religious experiences, and I will talk about that more when I discuss the fourth premise.)

What the principle of critical trust says is not that we take all of these experiences at face value permanently, but rather, that we treat them as “innocent until proven guilty,” as we tend to do for our physical perceptions. When two eyewitnesses describe a car crash and they disagree on some of the details – even major ones – it wouldn’t reasonable to assume that nothing happened at all. When someone tells you that they saw something unusual, it isn’t reasonable to assume right off the bat that they are lying or deluded. The critical trust approach says the same should go for religious experiences.

Many religious experiences are not overwhelmingly powerful, and a non-believer who has one, or something like it, may just brush it off. My own experiences in my relationship with God are generally of this modest variety. But a significant number of people throughout history have had quite powerful and vivid experiences of God, sometimes throughout their lifetime. (Kwan’s article cites some examples.)

For those people who have powerful and compelling experiences of God, is it really reasonable to say that they are not entitled to trust their experiences, at least initially? When they otherwise seem like honest and mentally stable people, is it really reasonable, before even examining the issue, to say that their beliefs based on those powerful experiences are simply the result of gullibility?

So I think that religious experiences should be allowed to count as at least some evidence for the truth of the beliefs that they form. The next two premises are about why, for some experiences, I think that evidence is strong enough to fully justify those beliefs.

Theistic Experiences are Well-Established

I am now going to focus on a subcategory of religious experiences, specifically, theistic experiences. Theistic experiences are those that the subjects take to be of God, that is, the all-powerful personal creator of the universe. The third premise of my epistemological argument is that theistic experiences constitute a well-established type, so that such experiences produce not merely some justification for their associated basic beliefs, but sufficient justification to accept those beliefs.

The criteria for being a well-established type of experience are:

  • experiences of that type occur to many different people and in many different situations,
  • the experiences are coherent with each other and with other types of experience, and
  • the experiences fit well into a worldview that best explains all of reality.

All three of these criteria are fulfilled by theistic experiences.

First, many people throughout the world, across cultures and eras of history, have theistic experiences. The majority of people worldwide are religious. The largest religious traditions, Christianity and Islam, are theistic, and a significant fraction of the adherents to those religions have had experiences of God. Theistic experiences are not limited to the Western world, either. There are theistic traditions within Hinduism, and indications of theistic beliefs in ancient China, for example. Even non-religious people sometimes have religious experiences, many of them theistic or compatible with a theistic worldview. (Some polls cited in Kwan’s article suggest that more than a third of the general population in the Western world have had a religious experience of some kind.)

All in all, it is plausible that hundreds of millions of people alive today have had experiences of God, and many more throughout the five thousand years of recorded human history. These are not a collection of isolated events. Rather, spanning continents and cultures, theistic encounters form part of the normal range of human experience.

Second, theistic experiences are generally coherent with each other. There is a rich diversity of ways in which people claim to experience God, but they are all unified by pointing to God as a personal and spiritual being who is the Ultimate Reality, the foundation of moral values, and the creator of the universe. All of the different modes of theistic experience listed above generally make sense in light of this concept of God. There are differing claims about the identity and nature of the God who is encountered in these experiences, but at least a common core of proposed truths about God can be extracted from these differing claims.

Furthermore, theistic experiences are generally coherent with all of our other types of experience. Most other religious experiences can be fit fairly comfortably in a theistic worldview, with the possible exception of monistic mystical experiences and experiences of Nirvana. (I’ll write a bit more about those when I discuss the next premise.) There is certainly no direct contradiction between the existence of the physical world revealed by our senses, and the existence of a spiritual reality revealed by our experiences of God. And our moral and rational intuitions are at home in a universe where the Ultimate Reality is a personal being.

Third and finally, theistic experiences are coherent with and even suggested by a worldview that (I believe) takes into account all the data and best explains all of reality – namely, a theistic worldview, and the worldview of Christianity in particular. I will let all the other arguments for God’s existence, many of which I will explore in future posts, stand in support of the claim that a theistic worldview is the best explanation of all the data.

(It may be objected that postulating the truth of a specific religious worldview can never be a good explanation for spiritual experiences from outside of that religious tradition. I will address that objection as part of my next post.)

All of this means that theistic experiences are a well-established type of experience: they are coherent and corroborated by other experiences, and so can be taken to provide sufficient justification for accepting the beliefs that we form in that context.

Logical Incoherence Objection

If the concept of God is not coherent, then experiences of God cannot be coherent either, which removes the justification for thinking that they are a well-established type. This is something that I’ll look at in more detail in the future, but suffice to say that I haven’t found any supposed contradictions that aren’t resolved by closer examination.

Even if the concept of God is coherent, the concept of a theistic experience itself might not be coherent: some critics of the epistemological argument contend that God is not a possible object of experience. Reasons for this may be that God’s properties are not the kinds of properties that can be given in our experience, or that it is impossible for our finite minds to experience his infinite attributes.

However, by those criteria, even physical entities are not possible objects of experience. The only things we really experience are mental qualia. But we still say that we can see physical objects, even if some of their properties (like mass and charge) are not directly present in our experience, and even if they are too large to be seen all at once. So there doesn’t seem to be a problem with experiencing God.

It is also worth noting that sensory-like perception is not the only way that we experience the world around us. Emotions and intuitive apprehensions can also convey meaning: these are an important component of our interpersonal experience, for example. Since theism contends that God is personal, this mode of encountering God is expected. So God may also be experienced via non-sensory phenomena, and the principle of critical trust still applies.

Impossibility of Individuation Objection

Another objection to this premise is that we can never prove that different theistic experiences are actually of the same God. But we can also never prove that different sensory experiences of the table in my living room of actually of the same physical object. The table could have been replaced by an indistinguishable one while I was away, for example.

The point is that we routinely use the principle of critical trust, along with inference to the best explanation, to identify and reidentify objects between different experiences. It is no different with experiences of God.

Objection of Non-Universality

As widespread as theistic experiences are, not everyone experiences them. This has been suggested as another reason why we should not take theistic experiences as a well-established type, arguing that well-established experiences should have the same level near-universality as our physical perceptions.

However, it is simply not true that experiences must be universal to be justifiably believed. Our sense experiences enjoy confirmation and corroboration far in excess of what is required to be reasonable, so I will certainly grant that they are better established than theistic experiences. But to require universality of all experiences before believing them is like saying that if a hockey player is not as great as Wayne Gretzky in his prime, he must be therefore be an incompetent hockey player who you would never want on your team.

There are relatively few people who experience perfect pitch (about 1 in 10,000 according to Wikipedia), but those who do are still justified in trusting their recognition of the absolute pitch of a note on the basis of their experience. Similarly, we will often believe something based on the testimony of a number of people considerably smaller than everyone available. If one person told you they had seen an airplane land on the highway, you might doubt it; if ten more people told you the same thing you would most likely believe it. If a hundred more people then told you, you might consider it even more confirmed, but mostly you would be thinking that you knew that already.

So universality is not required for a type of experience to be well-established.

Objection of Vagueness

Similarly, theistic experiences are usually not as vivid or detailed as our physical perceptions. But this is not always true: some people have very detailed visionary experiences of God. And in any case, experiences to not need to have the same level of vividness as our physical perceptions to be believed either. A person whose senses have been dulled by damage or old age is still justified in believing what they can discern from their experiences, even if those experiences are not as vivid as typical physical perceptions.

Other Disanalogy Objections

Critics of the epistemological argument might object to theistic experiences on a number of other ways that they are not analogous to sensory experiences – but unless the difference can be shown to be epistemically relevant, these are not good reasons for rejecting theistic experiences as a well-established type. They simply represent an unjustified preference for sensory experiences.

To press this point, memory is very different from sensory experiences in many ways, yet the justification for much of our knowledge about the physical world rests on memory – and memory cannot be non-circularly justified without the principle of critical trust. And similarly, inductive and abductive reasoning have important differences from deductive reasoning, but they are still rational and crucial in both everyday life and in the practice of science.

That is what I have to say about the third premise of the argument from religious experience. In my next post I will explore the final premise, and conclude my discussion of this argument.

The Epistemological Argument (I)

Why do I believe in God? The first reason is simply that I was raised to believe in God, and I have had experiences of his presence that confirm to me the truth of those beliefs. In other words, I believe in God on the basis of experience and testimony, two sources of properly basic belief. For many believers, these are, in fact, the primary reasons for belief in God – and my contention is that this is completely justified.

I have explored the concepts of experience and testimony as sources of properly basic belief earlier in my blog, so I will simply reiterate briefly:

Properly basic beliefs are beliefs that are justified because they have been formed in an appropriate way, grounded in the context of our experience, rather than being justified by some kind of rational argument from other beliefs.

Some of our beliefs must be properly basic for any of our beliefs to be rationally justified at all. Otherwise, every belief would require a rational argument from other justified beliefs in order to be justified, leading either to circular reasoning or to an impossible infinite regress of beliefs. Our belief system must rest on some kind of foundation.

The fact that a belief is formed in an appropriate, properly basic way does not mean that it is infallible or indefeasible. It merely means that such beliefs possess some inherent justification, providing a good reason to accept that belief, but one that can be overridden by other considerations.

The principle of critical trust essentially says that we should accept properly basic beliefs, because of their inherent justification, and that we should treat them impartially, not arbitrarily favouring some over others because of our preferences, but only assigning priority between them when we have good reasons to do so.

One of the valid reasons for allowing one source of basic beliefs to have priority over another, when those two sources are in direct conflict, is when one of the sources is better established than the other. We consider a particular type of experience to be well-established when it occurs in many different situations and to many different people, when the basic beliefs it produces are coherent with each other and with those from other types of experiences, and when it fits well into a worldview that explains and describes all of reality.

For example, our sense perception of the external physical world is an incredibly well-established type of experience, and is therefore a valid source of properly basic beliefs. The physical intuitions that we develop about the workings of the world around us are also a source of basic beliefs – but they are less direct and less well-established than sense perception. So if we have a basic belief from our physical intuitions that, say, heavier things fall faster than lighter things, that can be overridden by directly perceiving the outcome of an experiment which demonstrates that this intuition is false.

With all the above in mind, the epistemological argument for belief in God is this:

  1. The principle of critical trust is valid, so that if a certain type of experience is well-established, a person who has such an experience is justified in believing it, unless there is an overriding reason to disbelieve it.
  2. People have theistic experiences, that is, events that they take to be experiences of a personal being who is the ultimate source and foundation of reality – God.
  3. Theistic experiences are a well-established type of experience.
  4. Reasons to disbelieve theistic experiences are not successful.
  5. Therefore, we are justified in believing in God on the basis of our own theistic experiences.
  6. Testimony is also a valid source of basic beliefs.
  7. Therefore, we are also justified in believing in God on the basis of the reported theistic experiences of others.

This argument, or something similar to it, has been thoroughly developed by philosophers such as Richard Swinburne, William Alston, and Kai-man Kwan. It is more commonly known as the argument from religious experience. Though the aforementioned philosophers have articulated it far better than I can, I will explore the argument, and explain why I think it is a good one, in the next couple of posts.

The conclusions of the argument (5 and 7) follow logically if the premises (1 to 4, and 6) are true. So I will argue for the truth of the conclusions by defending the premises in turn.

The Principle of Critical Trust Once More

It is powerfully evident to me, after exploring the topic of epistemology, that the principle of critical trust is by far the most rational foundation available for a system of knowledge. Without granting inherent justification to some of our basic beliefs, none of our beliefs could be justified through reason. Furthermore, extending this initial trust to only a subset of our basic beliefs is arbitrary – the most natural approach is to initially trust all basic beliefs, and then critically examine them with all evidence in view.

(Once again for clarity, here by basic beliefs I mean those that are not arrived at via a conscious process of reasoning. Rather, they are naturally formed in the context of experience, or unconsciously formed through intuition, or received through testimony.)

Suppose you want to claim that your belief in the physical world is justified. In order to do this, you need to grant that the basic beliefs formed through your sensory experiences have inherent justification. But even more than that, you need to grant the same to beliefs formed from memory, or your knowledge would be limited to the fleeting present experience. And you need to grant the same to beliefs formed through introspection, or you could not be justified in believing that you were having experiences at all. And you need to grant the same to your rational intuitions, so you can know what you are justified in believing and what you are not, and so you can know how to use different forms of reasoning to support new beliefs.

Sensory experiences of the physical world are not the only experiences we have, either. We have interpersonal experiences, interacting with other people and naturally forming beliefs about their mental states as distinct from ours. We have moral and aesthetic experiences, forming beliefs about values that overlay states of affairs in the world around us. And a significant fraction of the human race has religious experiences, forming beliefs about a reality that transcends and precedes the universe.

All of these experiences are woven together in a seamless web, integrated together and difficult to isolate from each other. Impartiality in our examination of the evidence requires that we apply the principle of critical trust to all of our experiences and intuitions, not just some of them. Intellectual charity and humility require that we extend the same sort of initial trust, with subsequent critical evaluation, to the testimony of others.

So I think we have good reason to believe premises 1 and 6 of the argument. But there are some objections that people might raise against the idea that the principle of critical trust should apply to religious experiences, specifically. Here are some of them.

The Logical Gap Objection

Perhaps we cannot justify beliefs from religious experiences because there is no way to logically infer the existence of some objective reality based on nothing more than the subjective feeling produced by the experience. But we also can’t reason from our subjective sensory experiences to the existence of the physical world – we could just be hallucinating, or experiencing some kind of illusion. So this is as much of a problem for our belief in physical reality as it is for our belief in spiritual reality. To be consistent, we should apply the principle of critical trust to both.

The Privacy Objection

Maybe the problem with religious experiences is that they are private, like hallucinations or dreams. But our experiences of physical reality are also private, essentially occurring in our minds as subjective phenomenon. I can never directly compare my experience to yours; I can never know if my experience of the colour red is the same as yours, for example.

Certainly, verbal reports of sense experiences from different people can be compared, and are public in that sense – but the same is true of religious experiences. It is easier to do this with sense experience, because religious experiences aren’t as common – that’s a different objection, which I’ll address in the next post. But that means that religious experiences are only quantitatively (not qualitatively) different from our experiences of the physical world in terms of their privacy.

The Uncheckability Objection

So maybe the real problem is that there is no criteria by which we can verify whether a religious experience was an encounter with an objective reality, or just a subjective delusion. (This is the uncheckability objection.) Conversely, when we have a dream, we can examine the world around us to determine that the dream was not actually true.

Except that there are ways we can verify religious experiences. We can compare our experience to the experiences of others, and to the teachings of religions – which (most often) represent the distillations of spiritual experiences of whole communities throughout history. More generally, we can see if our experience is coherent with and explained by the worldview that best encompasses all the evidence.

This, of course, requires that we apply the principle of critical trust to religious experiences – but we would be just as unable to verify our experiences of the physical world without applying that principle to our sensory experiences. We can only really check sense experiences through other sense experiences, so it is not any less justifiable to check religious experiences through religious experiences.

The Theory-Ladenness Objection

One more objection to allowing religious experiences to provide justification for religious beliefs is that such experiences are theory-laden. Religious experiences, it is claimed, are so heavily influenced by the prior conceptual frameworks of those having the experiences that they are of no value for discovering objective truth whatsoever.

Of course, even ordinary perception is theory-laden: for example, what we experience visually can be influenced by what we expect to see. This kind of top-down visual processing can be recognized in optical illusions. Memory is also often strongly influenced by one’s conceptual framework. So again, this is only a quantitative difference, not a qualitative one, between religious experiences and forms of experience which we readily accept with critical trust. The question is whether the influence of one’s prior conceptual framework really does mangle religious experiences beyond all use, where it (presumably) does not do this for physical perception.

There are two things to note about this. For one, prior theory does not completely constrain the content of religious experiences. Many religious experiences are highly individualistic, and have content that is not clearly derived from the belief system of the person in question. And for two, interpretation in light of prior theory does not necessarily render an experience untrue. For example, our top-down visual processing often aids in perception rather than hindering it; it is the reason we can use a few punctuation marks like : – ) to rapidly convey meaning. The genuine significance of an experience can be missed through underinterpretation as well as through overinterpretation.

If the theory-ladenness of religious experience is a problem, it is a problem for sense experience as well. You cannot prove that our experiences of the physical world are less encumbered by prior theory than our religious experience are – not without arbitrarily extending initial trust to sense experiences while denying that trust to religious experiences. To avoid devolving into complete skepticism, it seems most reasonable to accept all our experiences, along with their integrated interpretations, as inherently justified, but fallible and subject to critical examination.

Continuing the Argument

So that is what I have to say for the first premise of the epistemological argument (and the sixth – as I have written before, it seems best to me to treat testimony as falling under the principle of critical trust as well). In my next two posts, I will look at the remaining premises, and further objections.

The Existence of God

In order to explain and organize all our disparate experiences of the world we live in, everyone goes through the process, consciously or unconsciously, of forming a worldview. A worldview is an overarching framework for understanding and interpreting reality. And what someone believes about God is, almost certainly, their worldview’s most defining characteristic.

Does God exist? Who is he? What is our relationship to him? These are incredibly important questions, impacting what we believe about what is right and wrong, about why we are here, about where we came from and where are ultimately going. This is not a matter of indifference. All meaning, value, and purpose is on the line. What we believe about God influences every aspect of our lives.

It is important, then, to think clearly and carefully about how we answer these questions – to seek the right answers to these questions. So my goal in this section of my blog is to lay out the most significant considerations that I can see pertaining to this matter – reasons for belief in God and reasons against that belief – and explain why I believe the way I do.

I will say, up front, my conclusion is that God exists. This is the belief I grew up with, so perhaps some of you reading my blog will dismiss my conclusion as mere confirmation bias writ large. In response to that, I simply say that I have made an honest attempt to examine the reasons for and against belief in God as objectively as possible. I find that there are serious considerations on both sides, but when taking the whole scope of human experience into account, that a theistic worldview (and specifically, a Christian worldview) is the most coherent one, and gives the best explanation for the evidence.

To those who would dismiss my conclusion as nothing more than the result of my own biases, I hope you carefully consider whether that blade cuts both ways. Is your dismissal of my conclusion based on valid, rational justification? If so, what is that justification? Have you examined both sides of this question objectively? If I cannot free myself of my biases, are you able to free yourself of yours?

(And if you think you have no biases about this, I think you need to look more closely. The broad implications that God’s existence has for why we are here, and how we ought to live, mean there is no one who has no skin in this game.)

With that being said, I hope that you will give me the benefit of the doubt, and believe me when I say that I have good reasons for believing in God. And because of the gravity of this matter, I sincerely believe it is of great importance for everyone – for you – to also look for the truth about it. Which is why I want to share my reasons in this blog.

So over the next few months I will be exploring the reasons for and against belief in God. Here’s a preview of what’s to come.

Reasons to Believe that God Exists

The Epistemological Argument. According to the principle of critical trust, the beliefs that we naturally form in the context of our experiences have some inherent justification. These basic beliefs are the foundation of all our other beliefs, and it is through them that we believe, for example, in the physical world around us. Belief in God is often like this – justified via our own direct experiences of God or via the common features of religious experiences that millions of people have had all over the world and throughout history.

The Cosmological Argument. Our rational intuitions support the principle of sufficient reason, which says that every contingent truth has an explanation. Applied to the existence of the universe, the principle leads to a necessarily existing being – God – as the best explanation for how the universe began, or why there is something rather than nothing.

The Teleological Argument. There are a number of lines of evidence suggesting that if the laws of physics or the initial conditions of the universe had been even slightly different, life – of any kind – would have been impossible. It is highly implausible to think that these conditions came about by chance, and the multiverse hypothesis does not solve the problem. These things are evidence for the existence of a Creator and Designer as the best explanation of fine-tuning of the universe.

The Noetic Argument. The existence of consciousness points to a reality beyond the physical universe, as it is extremely difficult to conceive of a natural mechanism that could produce the kind of conscious experiences and mind-body interaction that we observe. The existence of a supernatural Mind as the source of all reality is the best explanation of the existence of our own minds, and their embodiment.

The Axiological Argument. We intuitively feel the force of objective moral values and find ourselves bound by objective moral duties, yet in an atheistic worldview the most plausible reality is that these are nothing more than illusions, and that there is no right or wrong, or good or evil. So where do these values come from? A morally perfect, necessarily existing being, whose own character is the standard of goodness, is the best explanation for our moral experiences, and the only plausible ground for objective moral values and duties.

The axiological argument can actually be multiplied six ways, by permuting to rational and aesthetic values and duties as well as moral ones, and by seeking to explain our ability to know these aspects of reality as well as their ground of existence. Thus it is a rather fruitful source of justification for belief in God.

The Ontological Argument. A few plausible premises about the nature of perfection, and the basic structure of reality, surprisingly lead to the conclusion that a perfect being – God – must exist. This argument is the closest we get to proving through pure logic that God exists.

The Historical Argument. Two thousand years ago in a remote province of the Roman Empire, a man, Jesus of Nazareth, was executed and buried in a tomb. But then his body vanished, and men and women who had been following him began testifying that this Jesus had appeared to them, having been raised from the dead. They weren’t making it up – everything suggests they truly believed they had seen Jesus risen, and they continued to proclaim him even under threat of violence or death. Considering the extreme implausibility of any atheistic account of these events, the most coherent explanation of the evidence is that Jesus really did rise from the dead, and that he is who he said he is.

Reasons to Believe that God Does Not Exist

The Incoherence of Theism. Sometimes it is claimed that God cannot possibly exist, due to logical contradictions present in his supposed attributes. These include inconsistencies inherent in single attributes as well as contradictions between different attributes. Some atheists have even said that the proposition “God exists” is completely meaningless.

The Presumption of Atheism. Do we really even need a reason to believe that God does not exist? Isn’t it the default position? This is what a number of atheists claim, often alongside related objections: that theism isn’t even worth considering, either because it’s too improbable, or it doesn’t actually explain anything.

The Problem of Divine Hiddenness. If God really does exist, where is all the evidence? For all the arguments that theists present for their belief, the existence of God is not nearly as evident as it could be. Why doesn’t God make his presence obvious, when he supposedly wants people to know him? Perhaps it is because he isn’t there at all.

The Problem of Evil and Suffering. It is clear that there is a tremendous amount of suffering in the world, as well as moral evil (if you believe in such a thing as objective morality, as theists generally do). Yet if God is both all-loving and all-powerful, shouldn’t he both desire to prevent all this evil and suffering, and have the ability to do so? So why doesn’t he? Atheists say the answer the is obvious: it’s because he does not exist.

The Problem of Religious Pluralism. There are many different systems of religious belief throughout the world; and for most of history, what you believed about God was typically a matter of where you were raised. How could God allow this state of confusion – especially if knowing the truth about him is important for our ultimate salvation and eternal life? How is that fair? Atheists, saying all these systems are just made-up stories, will claim to have the best explanation for the great diversity of religious beliefs.

The Problem of Exclusivity. One of the most common objections to Christianity specifically is against its claim to exclusivity – that salvation and eternal life are through Jesus Christ alone. Is this really just? Compounding the problem, Christianity claims that an eternal punishment awaits those who are not saved – can this really be the work of a loving God? There are many people who vehemently think not.

These are the major arguments I have found for and against theism. (Let me know if you think I have missed any important ones.) In my next post, I’ll begin exploring these in more detail.

The Foundation

In this post I want to write up an overview of the foundation I’ve been laying for my belief system.

What is truth? Truth is the correspondence of meaning to reality. A proposition is true if, and only if, it refers to a state of affairs that occurs in reality.

Is truth relative or absolute? Truth is absolute. Although everyone has their own perspective from which to view reality, reality itself is independent of any perspective. A proposition is either true or false and not both, and it has the same truth value for all observers.

What is belief? Belief is the mental state of accepting a proposition as true.

What is knowledge? Knowledge is validly justified true belief. Justification is valid when it appropriately links the belief to the truth. (See also here and here.)

How can we justify beliefs? Beliefs can be justified from other beliefs through reasoning, or they can be inherently justified if they are formed in an appropriate way.

Justification with reference to other beliefs:

Justification without reference to other beliefs:

How can we form a belief system? I think we all use the following approach, to some extent:

  • Extend initial trust to our beliefs formed from experience, intuition and testimony.
  • Create a worldview to explain as much of our experience as possible.
  • Sift our beliefs according to our worldview to create a coherent and consistent system.

This is a dynamic and iterative process, and we need to use critical thinking throughout. Our worldview may need to be adjusted if enough evidence conflicts with it.

Can we know? Yes, we can know things, and we can know that we know them. Justified belief is sufficient for a knowledge claim, and the claim will be correct if the belief is true and the justification is valid. Extreme skepticism, the claim that we can never know anything at all, is ultimately self-refuting.

How do I know all these things? How do I get my belief system off the ground? Intuition is critical in knowing these foundational truths, especially in evaluating the different options that are learned through testimony, experience, and intuition itself. And these intuitions are also supported by reason.


I’ve attempted to justify all of these claims in the posts where I made them, so you can go back and read those for more detail on how I know all these things. Have I justified them sufficiently? By all means, leave a comment or send me a message if you think that isn’t the case. I don’t believe I’ve missed anything important, but I certainly want to know if I have.

So that’s the foundation for my belief system, or at least, a sufficiently sturdy one for the time being. In the next post, I’m going to write about some different approaches to truth and knowledge, and the alleged tensions between them.

Then, I will finally be able to get going on the specifics of what I believe about the nature of reality, and the things that are in it.

How to Seek Knowledge

If the different ways that we justify our beliefs are the building materials for a structure of beliefs, then perhaps I can call the process by which we evaluate and adjust our beliefs the scaffolding for that structure. That is the topic of this post.

First, though, I want to make a couple of observations about the principle of critical trust that I presented in the last couple of posts. The essence of this principle is found in the two intellectual virtues that I explored earlier, critical thinking and epistemic faith. In using this principle, we extend initial trust to the beliefs that we naturally form from conscious experience, intuition, and testimony. Then we sift through those beliefs to try and discard the ones that are false, and strengthen the ones that are true.

The first observation I want to make here is that the principle of critical trust is not an “anything goes” principle. It does not mean we can believe whatever we want. Rather, it means we start by believing that things are the way they seem to be, on the basis of our conscious experience, intuition, and testimony – these initial beliefs must still have some kind of justification – and then we use reasoning to try and figure out the way things actually are.

The second observation is that, although the justification for these initial beliefs is not free, it is not all that costly either. We can usually find justification for what we want to believe, if we look for it. That is why it is important to weigh the justification both for and against a belief, rather than just looking at one side.

As a third observation, a corollary of the principle of critical trust is that when a belief is defeated by reasons to disbelieve it, it is rational to retain as much of the content of the belief as possible. For example, if you think you recognize your friend John on the street, but then later find out he was not in the city, you wouldn’t immediately think you had hallucinated the whole experience. You would think you had just seen someone who looked like John.

Worldview Formation

When I talk about constructing a belief system, what I principally have in mind is the formulation of a worldview, a comprehensive theory or perspective for categorizing, explaining, and interpreting all of reality. A belief system is essentially a worldview and the outworking of that worldview in the way that it interprets the world.

Everyone has a worldview, whether consciously or not – we all go through the process of creating an explanation and interpretation of everything we experience. We don’t have the capacity to deal with all of the diverse truths about reality independently. A worldview allows us to deal with all these truths in a unified way.

So, the principle of critical trust, and the need for a worldview, together suggest the following approach for forming, evaluating, and adjusting our whole belief system.

  • Presumptive Data: as presumptive data, accept that things are the way they seem to be, based on the sum of one’s conscious experiences and intuitions, and the testimony received from others. All of these data have a small amount of initial justification.
  • Initial Sifting: some of the presumptive data are likely to conflict with others. Sort the data into maximal consistent subsets (sets that contain as many beliefs as they can without containing a contradiction), and believe the subset with the most initial justification (rejecting the beliefs that conflict with this subset).
  • Worldview Formation: based on the beliefs accepted from sifting, form a worldview that explains as many of one’s beliefs as possible (principally, using inference to the best explanation).
  • Feedback Sifting: based on one’s worldview, some of the initially accepted beliefs may be rejected, and some of the initially rejected beliefs may be accepted. New presumptive data may be brought into consideration from re-interpretation of one’s experiences, intuitions, and received testimony in light of the new worldview. These two principles are important here:
    • Principle of Epistemic Defeat: reject beliefs that are in conflict with the best explanation of a vast number of other accepted beliefs. When beliefs are defeated in this way, retain as much of their content as possible that is undefeated.
    • Principle of Epistemic Enhancement: when an accepted belief is coherent with or suggested by the best explanation of a vast number of other accepted beliefs, its justification is enhanced.
  • Re-evaluation: New data or new understanding of old data may challenge one’s worldview, eventually forcing a re-evaluation and re-formation of the worldview when the data that cannot be fit into it acquires enough weight.

By going through this process, forming and re-evaluating our worldview and the whole system of beliefs associated with it, we will (hopefully) come to believe more and more truths, and disbelieve more and more falsehoods, in a validly justified way. That is, we will come to acquire more and more knowledge.

But the key to this process being successful in the long run is having the right worldview. If your foundational beliefs are true, you are more likely to interpret the data correctly, leading to further knowledge. If your foundational beliefs are false, your interpretation of the data is more likely to be wrong, impeding the search for knowledge.

Pilate’s Question

So I think I have adequately covered the nature of knowledge, and when it is reasonable to hold a belief. Now I come to a question that has been hovering in the background for a while. Belief is an attitude of accepting a proposition as true. Knowledge is validly justified true belief. I have claimed that it is important to hold a true worldview. And all throughout, I have been upholding the value of rationality – but the value of rationality is just that it allows us to know what is true.

But what is truth?

That is the topic I will turn to in my next post.

Building Materials (I): Deductive Reasoning

I’ve been surveying the ground on which to build a comprehensive belief system. Here are the main conclusions that I have come to so far:

  • A belief is an attitude of accepting a proposition as true.
  • Knowledge, the kind of belief that we want to hold, is validly justified true belief.
  • Justification for a belief is valid if it is appropriately connected to the truth of the belief.
  • Some beliefs are justified by other beliefs, and some beliefs are properly basic, that is, justified without reference to other beliefs.
  • Some of our properly basic beliefs are things we just know intuitively; among these are beliefs about what counts as knowledge and what doesn’t.

Now I am going to take a look at the “materials” out of which a belief system can be built: the ways that we actually use to justify our beliefs, in practice. I think the different forms of rational justification can be grouped into five categories:

  • Deductive reasoning
  • Abductive or inductive reasoning
  • Experience
  • Intuition
  • Testimony

In other words, there are five different ways to answer the question, “How do I know that?”

  • “It follows logically from these other things I know”
  • “It is the best explanation of these other things I know”
  • “I directly observe it in my conscious experience”
  • “I just intuitively see that it is true”
  • “Someone told me so”

The different forms of reasoning justify beliefs using other beliefs, while experience and intuition are ways of forming properly basic beliefs. Testimony can also be treated as a source of properly basic beliefs.

I am focusing here on rational justification, but I think in some cases there can be pragmatic justification for a belief. That is, sometimes you can be warranted in holding a belief, even when you do not have sufficient rational justification for it, because of the useful consequences of holding that belief. In fact, I think there are probably situations where you can’t actually find rational justification for a belief until after you have accepted that belief on pragmatic grounds. (You could argue that my project here of trying to discover the nature of knowledge and justification is such a situation.) But for now I want to try to keep pragmatic and rational justification distinct, and build my belief system using rational justification where I can. (And I also think that it is only rational justification, not pragmatic justification, that confers knowledge.)

Alright. With that preamble, the first “building material” that I will look at is deduction.

Deductive Reasoning

Deductive reasoning is the use of logic to derive a conclusion from one or more premises. Here is an example of a deductive argument:

  • Premise: If it is raining, then the ground is wet outside.
  • Premise: It is raining.
  • Conclusion: Therefore, the ground is wet outside.

Deductive arguments derive conclusions from premises using certain logical rules, called rules of deduction. If those rules are followed correctly, and the premises of the argument are true, then the conclusion of the argument is true. (Deductive reasoning can also be used where the premises are not certain, but where they are thought to have some probability of all being true: then a valid deductive argument guarantees the conclusion is at least that likely to be true.)

The above argument correctly uses the rule of conditional elimination (often called by its classical name, modus ponens) to derive its conclusion from its two premises. So, if those two premises are true, then the conclusion is guaranteed to be true. But the conclusion could still fail to be true if either of the premises is false. (For example, maybe it isn’t raining, or maybe rain doesn’t make the ground wet because the ground happens to be made of a super-absorbent material.)

Deductive arguments can also fail if they do not correctly follow the rules of deduction. For example:

  • Premise: If it is raining, then the ground is wet outside.
  • Premise: The ground is wet outside.
  • Conclusion: Therefore, it is raining.

This argument is invalid, because the truth of the conclusion is not guaranteed by the truth of the premises. (There could be another reason that the ground is wet; for example, maybe it isn’t raining but someone decided to dump buckets of water on the ground.) An incorrect use of the rules of deduction is called a formal fallacy. This example commits the fallacy called affirming the consequent.

Logical arguments can also suffer from informal fallacies. These have to do with the content of the argument, rather than its structure. For example:

  • Premise: Either pigs can fly, or the Earth is approximately a sphere.
  • Premise: Pigs cannot fly.
  • Conclusion: Therefore, the Earth is approximately a sphere.

This argument is logically valid and its premises are true. But the only reason you have for believing the first premise is that you already believe the conclusion; so this argument tries to support the conclusion using the conclusion itself. This is an informal fallacy often called begging the question.

So, if a deductive argument is free from any fallacies, and you justifiably believe the premises (or at least think it is likely that they are all true), then the argument provides good justification for its conclusion. Because the truth of the conclusion rests on the truth of the premises, for such justification to be valid, the premises should be true and themselves validly justified.

That is the first form of justification. In my next post, I will look at other forms of reasoning that we can use to justify our beliefs.