Some sound theistic arguments

Argument 1:

1. Possibly, the Principle of Sufficient Reason (PSR) is true.
2. Necessarily, if the PSR is true, then there is a causally efficacious necessary being.
3. Therefore, possibly, there is a necessary causally efficacious being.
4. Therefore, actually, there is a necessary possibly causally efficacious being.

Argument 2:
Let @ be the actual world. Say that a being is omnipotent* provided it is omnipotent at at least some explanatory point in the history of the world (so omnipotence* is prima facie compatible with giving up omnipotence).

1. Possibly, there is an omnipotent being.
2. Necessarily, if x is omnipotent, then x exists at @.
3. Necessarily, any omnipotent being is essentially omnipotent*.
4. Therefore, there is an essentially omnipotent* being.

Premises (2) and (3) need support. First, necessarily, a being is only omnipotent if it could create me (directly or mediately). But by essentiality of origins I could be created by a being only if I am created by the being. Therefore, if there is a being that could create me, that being creates me at @, and hence exists at @. Thus, (2). Also, plausibly, an omnipotent being could be the First Cause in any possible world. Hence, an omnipotent being must be a necessary being, and hence exist at @. Thus, (2).
What about (3)? Well, an omnipotent being could exercise its omnipotence to put itself in any state possible to it. Suppose it's possible for an omnipotent being to fail to be omnipotent*. Then the omnipotent being could make itself be non-omnipotent* by exercising its omnipotence. But then the being would be omnipotent at some explanatory point in that world where it makes itself non-omnipotent*, and hence it would be omnipotent* there. So absurdity arises. So it's not possible for an omnipotent being to fail to be omnipotent*.

Argument 3:
Say that x knows* p iff x knows p or knows some proposition of which p is a conjunct.

1. Possibly, there is a being x such that for any proposition p that could be true, x could know p.
2. Therefore let w be a world and x a being such that x exists at w and for any proposition p, if p could be true, x could know p.
3. Therefore, if w* is any possible world and p be any proposition true at w*, then x could know that w* is actual and p.
4. x could know that w* is actual and p only at w*.
5. Therefore, if w* is a possible world and p is true at w*, then x exists at w* and knows* that p at w*.
6. Therefore, there is a being that exists at every world and knows* every truth at every world.

Johnson's framework for theistic arguments

Occasionally, I've been offering theistic arguments that border on begging the question. Here, for instance, is one that's basically due to Kant, but transposed into an argument in a way that Kant would not approve of:

1. (Premise) We should be grateful for the wondrous universe.
2. (Premise) If something is not the product of agency, we should not be grateful for it.
3. Therefore, the wondrous universe is the product of agency.

The argument is indisputably valid.[note 1] Moreover, if theism is true, it is also sound, and I do take theism to be true. But soundness is, of course, not enough for a good argument. While premise (2) is pretty plausible (in the objective sense of "should"), it feels like premise (1) "begs the question".

Nonetheless, I think there could be something to (1)-(3). Dan Johnson, in the January 2009 issue of Faith and Philosophy has a fascinating little article on the ontological and cosmological arguments. He argues that a certain kind of circularity is not vicious. Suppose that I know p₁. I then infer p₂ from p₁ in such a way that I also know p₂. I then non-rationally (or irrationally) stop believing p₁, but as it happens, I continue to believe p₂. It will then often be the case that there will be a good argument from p₂ back to p₁ (perhaps given some auxiliary premises), and if I use that argument, I will be able to regain my knowledge of p₁. This is true even though there is a circularity: from p₁, to p₂, and back to p₁. Here is an uncontroversial example: I am told my hotel room is 314. I infer that my hotel room is the first three digits of pi. I then forget that my hotel room is 314, but continue to believe it is the first three digits of pi. I then infer that my hotel room is 314.

Johnson proposes that by the sensus divinitatis one may come to know that God exists (actually, throughout this, I can't remember if he talks of knowledge or justified belief). One may then infer from this various things, such as that possibly God exists. Then, one irrationally rejects the existence of God (it does not have to be a part of the theory that every rejection of the existence of God is irrational), but some of the things one inferred from that belief remain. And arguments like the S5 ontological argument then make it possible to recover the knowledge of the existence of God from the things that one had inferred from that belief. Johnson also applies this to the cosmological argument.

This same structure may be present in my Kantian argument. By the sensus divinitatis one comes to know that God exists (obviously this is not a Kantian idea!). One infers that the universe is such that we should be grateful for it. One then irrationally comes to be an atheist (again, there is need be no claim that every atheist is irrationally such), but one continues to believe that gratitude is an appropriate response to the universe. And if that belief is sufficiently deeply engrained, one can reason back from it to theism or at least to agency behind the universe.

Now let me move a little beyond the Johnson paper. I think it is not necessary for this structure that the initial knowledge of God's existence come from the sensus divinitatis. Any other way of having knowledge of God's existence will do—say, by argument or testimony. In fact, it is not even necessary for this structure that one oneself ever had the knowledge or even belief that God exists. Suppose, for instance, one's parents knew that God exists (in whatever way), and inferred from this that the universe is worthy of gratitude. They then instilled this belief in one, and did so in such a way as to be knowledge-transmitting. (Surely, value beliefs can be instilled in such a way.) But they did not instill the belief that God exists (maybe because they thought that the existence of God was something everybody should figure out for themselves). One then knows (1), and can infer (3).

This transmission can be mediated by the wider culture, too. Culture can transmit knowledge, whether scientific or normative, and arguments can work at a cultural level. It could be that a theistic culture where the existence of God was known grew into a culture where (1) was known. The knowledge of (1) can remain even if the culture non-rationally rejects the existence of God (as American culture has not done, and might or might not do in the future). And then the individual can acquire the knowledge of (1) from the culture (we don't need to attribute knowledge to the culture if we don't want to; we can just talk of knowledge had by individuals participating in the culture), and then infer (3).

I think there are probably many consequences of theism that are embedded in the culture, from which consequences one can infer back to theism. If the participants in the culture knew theism to be true when these consequences were derived, then it is perfectly legitimate to reason back from these consequences to theism.