I am an atheist; I don't believe in God. Any gods, to be precise. Well, I suppose I believe in a thinly-defined "god" that is just "whatever caused the universe to exist", but who knows what that is? I also, for the record, believe in "nature itself" and "the way things are". But those thin definitions certainly don't seem like what most religions are describing. Religions usually seem to think He's some type of guy. Which I think is unlikely, because a guy implies a mind, and minds are very complex things, and it seems simpler to me to assume the cause of the universe is probably something less complex than a mind of some type appearing at random. (My preferred solution is that the existence of the universe may be merely a brute fact.)

  (Some religious philosophers argue that God is not a mind, but rather something that just has properties analogous to a mind in some ways. I think this usually flies in the face of the religious texts they are pretending to interpret, but also that the mind-like object they posit is not really simpler than a mind, so whatever.)

  Also, (pāce) it seems to me irrational to believe in God. It just seems like a ridiculous thing to do, and if you considered it rationally for like a day then you'd stop. But is it? Is it irrational? A large journey through philosophy I have taken over the past couple years is discovering that it's not irrational, in certain technical philosophical senses. I think in two senses it isn't, but in the original sense I meant by "irrational" when I first concluded belief in God was irrational, it still is irrational.

  1. The first sense of "irrationality" is "disobeying the probability-conservation rules proved by bayes theorem". I think it's perfectly rational to believe in God under this definition. After all, maybe you just have a very strong prior on God existing. As long as you do the updates correctly, you can hold really any posterior at the end, based on your priors. So, technically, you could be rational and believe in God. (See also, my forthcoming essay on Turing Machines and belief in God.) Although, perhaps in practice many religious people do disobey bayes theorem when updating their beliefs, and are thus technically irrational; since this happens privately in their head, I don't know either way.

  (As I've said elsewhere, most people don't seem to actually care about being, or be trying to be, rational, so I guess it would be surprising if all people everywhere were bayesianly rational about religious matters. But maybe no worse than usual.)

  2. And why would you have such a strong prior? Well, this leads into the second sense: I think it can be rational to believe in God in a day-to-day sense. Consider: I've never seen the Eiffel Tower, besides depictions, but everyone around me has told me it exists, so I assume it does. I've never met Napoleon, but everyone around me seems to think he was real, so I assume he was a real guy who did what they said he did. I believe electrons exist and underpin electromagnetism, even though I could not personally conduct a single experiment that proves this, merely because this is the knowledge society has passed down to me. I think it's completely rational to live in a religious setting and assume that people who tell you God exists aren't mistaken; after all, they seem to know a lot of other things rationally.

  3. However, that societal knowledge only gets you so far. For one thing, maybe your society (in aggregate) thinks the existence or character of God is an open and important question (I think this has basically been true in the West since 1600 or something). Or perhaps for other reasons, you begin to consider the question on its own merits. The third and original sense of rationality under consideration is if you can sit down, with non-insane priors, and a keen intellect, and no irrational commitment to either side, and seriously consider all of the good arguments and evidence for and against God that we have available, and come to the conclusion that God exists. The text of holy scriptures; the teachings of various religious orders; The Problem Of Evil; Hume's Argument Against Miracles; The Invisible Pink Unicorn; Thomas Aquinas; The Kalaam Cosmological Argument; Pascal's Wager; Leap Of Faith; etc etc etc ... The list is very long and you will probably access it at random, like all intellectual inquiry. You will probably make your decision before exhausting the entire history of philosophy of religion (this is Hubbard's Second Law: as you gain more information about a topic, the expected value of learning additional information decreases, because you know more about the topic so you have less to learn from the new information). This is fine; you must merely make your exploration in a non-insane order, to accompany your non-insane priors, to get the right sense of rationality.

  I think the answer is no. I think you cannot consider this issue in this (substantively) rational way and come to the conclusion that God exists. Please note that I *have no additional argument for this*. The "argument" I could offer is, itself, just the consideration of all the arguments for and against religion, and coming to the conclusion that the case for atheism is overwhelming. Treating your belief in God like any other belief you hold that you might seriously evaluate leads you pretty promptly to the conclusion that God doesn't exist. Once, as a child, I said to my father, "you can't prove that dragons DON'T exist" and he said "with that logic, you could argue for anything", and that's always stuck with me.

  (As an analogy, consider considering an argument that 2+2=4 (starting, I suppose, from agreed-upon premises that 1+1=2 and 1+1+1+1=4, and maybe some others to properly characterize +). I think you can technically have a prior strongly enough for 2+2≠4 that it will withstand the proof, and leave you with a posterior that 2+2≠4. Also, if your society was telling you often that 2+2≠4, it might make sense to hold that belief if you didn't properly look into it. But upon investigating it yourself, any (substantively) rational person would conclude 2+2=4. That's the sort of thing I mean by it being irrational to believe in God. The case about God is much more complex than the case about 4, however!)

  Heck, if you're like most religious people in the modern day, just treating your religion like any other religion would suffice. Their miracles are fake and their arguments are crummy. If you arrived that the denigration of the other religion using reason, you could probably apply the same reasoning to your own religion and reach the same conclusion.

  I suppose I could offer one other weak argument: philosophers are people who professionally consider arguments about philosophical topics, like whether or not God exists. They are also on average pretty smart people in general. Most philosophers do not believe God exists. (Most philosophers of religion do believe God exists, which I (pāce) chalk up to selection effects.) So the aggregate opinion of philosophers is weak evidence, perhaps evidence enough to counter the aggregate opinion of common people. But life has taught us that it is easy enough for a group of smart people to all fall into the wrong belief for various reasons, so I do not claim this is very strong evidence.

  (Sidebar: am I agnostic or atheist? I think the term "agnostic" means you don't think you know that God exists nor do you think you know that God doesn't exist, or you have no opinion on the matter. Meanwhile, the term "atheist" means you think you know that God doesn't exist. (My impression is these terms have shifted around in recent history, so maybe these senses are relatively newly settled.) Although it's technically impossible (via bayes theorem) to know that God doesn't exist with absolute certainty, it's technically impossible to know any proposition with absolute certainty. And I think my confidence is high enough, and my epistemic attitude in the right comportment, to say that I think I know there is no God. So I'm an atheist. And I rib agnostics for being cowards sometimes, because (as above) I think the right position is pretty self-evident—but, really, it's fine for the process of consideration to take as long as it needs, and during that process you're an agnostic by definition I guess.

  Note that this *doesn't* mean I couldn't change my mind on the matter. You can be (regularly, not absolutely) certain about something but change your mind later. For example, I think I know my own address, with incredible certainty, but if I looked at all my records and found I was somehow mistaken, I would change my mind.)

  There's another interesting consideration here: direct religious experience. Some people think they've seen God in a vision, or whatever. As a good bayesian, I think this does count as evidence for God. And, it's probably weak evidence if you were dreaming or doing drugs or having a stroke or something, but if you were just in a perfectly normal medical state, then I suppose it's fairly strong evidence for you personally. But pretty weak evidence for me, because I didn't have the experience, and ghost stories are a dime a dozen. In fact, you might want to decrease your credence in whatever knowledge you think you gained thereby, after hearing about all the various visions people have had throughout history, in different times and cultures, that they think have affirmed their particular conception of the divine. But, hey, maybe even with that consideration, your vision rationally convinces you God exists; I don't know.

  The same goes for other putatively supernatural phenomena like faith-healing. Most faith-healers are frauds, lucky, and/or placebomancers. But if you saw some guy walk through the air and then cure your bone cancer, who am I to conclusively say you didn't see something I didn't see? Remain skeptical, but if you find evidence, then take it. I have long held that if a faith healer could instantly and permanently cure my vision so I didn't need glasses, I would immediately convert to their religion; they clearly have something going on. Alas, most faith healers have far less falsifiable displays of the gifts of the spirit (I wonder why⸮). But, anyway, the general point is acknowledging that you can have epistemic justification that others can't, due to your private experiences. Technically we should be able to Aumann-agreement our way out of this, but (pāce) let's be honest: neither of us are perfectly rational theoretical agents, and even if I were to approximate one I would have reason to suspect you were not also approximating one. So let us, indeed, agree to disagree.

  By the way, I don't think it's super important for most religious people to not be irrational this way. I think this is a case of Rational Irrationality. Since there is no God, there are no huge consequences to being wrong about this, at least with the people I interact with regularly. There are some downsides, like people occasionally believing they have a divine mandate to kill (the marginal impact of this over the normal human rate of violence seems low, tbh; only a few extra killings, at least with the religions of my interlocutors), but in a utilitarian sense this is probably outweighed by the sense of serenity that a belief in God causes some people to feel. (Shortcut to stoic virtue?!) And, furthermore, a lot of religious morality and guidelines on how to live your life are pretty good, and honorable, and just. (I believe this even though I grew up in the early 2000s, when a lot of public discourse was centered around gay marriage (which I think is fine) and the religious opposition to it. I think this was just an edge-case that was forced into salience by being the center of conflict. Most religious advice is about being a good person.) As kind of a weird little philosopher guy, I believe truth is inherently good, and it's inherently good to not believe false things... but, you know, you have to pick your battles; there are better good things I can work on in this world, and if someone wants to recalcitrantly believe a wrong religion, that's only a very slight misfortune.

  (A sort of interesting question is, if I could press a button to magically remove religion from the world tomorrow, should I? *(Stipulate for this hypothetical that all religions are false.)* (Also, stipulate that the method by which the button works is not in itself immoral, like mind control: perhaps the button just presents to each person a true, convincing argument that convinces them that there is no God, but that this is OK, and they remain calm.) It's hard to say. I think there are some extremely bad edge-cases caused by religion (eg, various terrorist attacks), but it also probably prevents some extremely bad edge-cases (eg, other various terrorist attacks). I think the two probably do not perfectly balance. I know I said terrorist attacks just now, but I think some mundane religious practices are actually quite bad, morally speaking. But a lot of religious practices probably bring people joy, over and above what they get through a secular gathering. So, I don't know. I would probably do it. Truth is good, after all.)