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drake007: If no one has comprehensive knowledge of the universe, then no one can have any knowledge of the universe. Only God could have comprehensive knowledge of the universe. We have some knowledge of the universe. Therefore, God exists. Do you subscribe to this argument? Nick sent me this.

Jimmy Stephens: Yeah, that’s a good summary of the unitary-knowledge argument or problem of omniscience.

drake007: Interesting, ok. Can you explain P1? Why would that be the case?

Jimmy Stephens: My responses will be broken up until I’m at work. In brief summary, the reasoning might look like this:

In order to know anything, we must know that human knowledge is possible. It is impossible to possess an item of knowledge unless one also possesses this item of knowledge: knowledge is possible. Suppose knowledge is JTB, true justified belief. That means whatever J we have for the true belief that knowledge is possible, it will have to do the hard job of ruling out all skeptical scenarios. It will have to ensure that every single fact in reality accommodates and in no way undermines the possibility of human knowledge. In short, to know that human knowledge is possible is to know that all facts are perfectly coordinated to human consciousness.

Briefly consider the alternative. Suppose we believe that knowledge is possible. Suppose also that the reasons we enlist to justify that belief do not ensure that all facts are consistent with the possibility of human knowledge. In other words, our justification leaves open the possibility of global skepticism. That would just mean our belief that knowledge is possible is an assumption, not knowledge. It follows that if we do not know that knowledge is possible, then we cannot know that knowledge is possible without Christian revelation. And if we cannot know that knowledge is possible without Christian revelation, then unbelief is irrational de facto.

This is just a way of saying, a precondition of unbelief being a rational state of mind is for the unbeliever to know that knowledge is possible. And a precondition of knowing that knowledge is possible is accessing some reason that accomplishes the interlocked jobs of (a) ruling out all skeptical scenarios and (b) showing all facts in reality accommodate human consciousness.

Since this is impossible without omniscience, God is required to doubt the existence of God, showing that doubting God is a self-refuting state of mind.

drake007: I will get back to you soon. “It is impossible to possess an item of knowledge unless one also possesses this item of knowledge: knowledge is possible.” This is known as the KK principle, and internalists about knowledge will find it plausible, while externalists about knowledge will tend to reject it. So keep in mind that if you’re relying on this principle, you’re likely assuming a substantive view of knowledge that many philosophers will reject.

“That means whatever J we have for the true belief that knowledge is possible, it will have to do the hard job of ruling out all skeptical scenarios.” This too supposes internalism, this time about justification. Internalism about justification is on stronger footing, I think, than internalism about knowledge. Still, it helps to be aware of these commitments.

That aside, here’s a challenge: does it seem right that to justifiably believe that Trump is president I have to be able to rule out, via my justification, the possibility that an evil demon is deceiving me? Many people will think that’s too strong, so that’s something else to consider.

“In short, to know that human knowledge is possible is to know that all facts are perfectly coordinated to human consciousness.” It’s not entirely clear to me what this means, but the first issue is, couldn’t there be facts that no human knows, or ever could know? That seems plausible, but what you said above rules it out, and it’s not clear why we should accept that ruling out.

“It follows that if we do not know that knowledge is possible, then we cannot know that knowledge is possible without Christian revelation.” Why think that? Why not Muslim revelation? Why not some other non-religious (or not obviously religious) alternative, e.g., a grasp of the Platonic forms?

“God is required to doubt the existence of God, showing that doubting God is a self-refuting state of mind.” I can tell you’re running a sort of presuppositional argument. One way to think about such arguments is on the analogy with what Kant was doing in the CoPR, i.e., we start with some phenomenon we all accept (with your argument, that we know things) and then try to lay bare the necessary conditions of this phenomenon (with your argument, the existence of God). There are a lot of problems with these arguments, I think, which can vary depending on the argument. The big one is that there’s always this utterly unexplained leap at the end to the god of Christianity or to the Bible, or to something similar, but the version you’re working on will face the challenges above as well.

Apologize for the length.

Jimmy Stephens: No problem, man. I’ll reply when I can.

drake007: Cool Cool.

Jimmy Stephens: This is known as the KK principle. . . I don’t think this is the KK principle. As I understand it, the KK principle requires that for every item of knowledge, self-consciousness about that knowledge. Here, we’re just maintaining what’s constitutive of knowledge. It’s no more possible to believe in squares without believing that there are possibly four-sided objects. Likewise, knowing anything requires knowing that knowledge is possible – it’s part and parcel to any epistemic transaction.

This too supposes internalism, this time about justification. . . Sure, but we could suppose a non-JTB model of knowledge and repose the issue for externalism. Internalism isn’t necessary. It’s just easier to spell out the problem if we pick a foil model. On externalism, whatever mechanism produces warranted belief will only warrant those beliefs as long as it warrants belief that warranted belief is possible in the first place. Externalism doesn’t get us off the hook by default.

Does it seem right that to justifiably believe that Trump is president I have to be able to rule out, via my justification, the possibility that an evil demon is deceiving me? This just sounds like we’re asking about whether the challenge “seems” right. Yes, I think the challenge is right.

It’s not entirely clear to me what this means, but the first issue is, couldn’t there be facts that no human knows, or ever could know? That seems plausible, but what you said above rules it out, and it’s not clear why we should accept that ruling out. Actually, I think that’s to concede the argument. Absolutely, there are things humans cannot know. But only by knowing everything could we ensure that all facts in reality concur with the possibility of knowledge in the first place. It’s like checking the drawers in your room for monsters. Only if you can check all the drawers exhaustively can you rest assured. But as you note: we just can’t open and check all the drawers.

Why think that? Why not Muslim revelation? Why not some other non-religious (or not obviously religious) alternative, e.g., a grasp of the Platonic forms? Knowing that anything but Christianity is possible requires knowing that knowledge is possible in the first place. Once concession to the argument is made, the conceder has doffed their epistemic resources needed to doubt the Christian claims. To clarify, we should look back on the situation we find ourselves in. Both of us meet the question, “Can we know knowledge is possible?” Both of us have different responses to this question. Those responses constitute entire epistemic perspectives, in fact, whole worldviews. One worldview is that of unbelief, where one is committed to the agenda of autonomy, that we can live without needing Christian revelation. The other worldview (mine) is the Reformed Christian position, where everything in human life presupposes Christian revelation. Which answer suffices?

The problem with bringing up Muslim, Platonic, and alternative worldviews is threefold:

1.) It is inconsistent for you to believe these mutually exclusive positions compose a set of possible alternatives. That’s just to say that position-x-that-entails-the-impossibility-of-y and position-y-that-entails-the-impossibility-of-x are both epistemically possible. No, at face value, that’s epistemically impossible. In fact, this is not a list of possible alternatives, but really one overarching worldview that says reality is underdetermined, and here are the available interpretations. Well, if reality is underdetermined, so is this claim itself, and we find ourselves refuted.

2.) It is inconsistent with your own epistemology to posit worldviews that undermine the very epistemic resources you use to posit them in the first place.

3.) Positing alternative worldviews requires possessing the one true worldview in which knowing what’s possible is possible in the first place.

In light of (1), (2), and (3), appealing to “alternatives” is fallacious and suggests that one’s current state of unbelief has no rational basis. If it did, alternatives wouldn’t be needed. And if it did, alternatives wouldn’t be possible.

The big one is that there’s always this utterly unexplained leap at the end to the god of Christianity, or to the Bible, or to something similar, but the version you’re working on will face the challenges above as well. We’d need to see this spelled out, but I would enjoy going over this type of objection. In my experience, this sort of objection ends up making the same essential mistake made in the “alternatives” strategy. Namely, it just assumes we can talk about what’s possible without already possessing that worldview in virtue of which we know knowledge of possibility is possible. It gets the cart entirely in front of the horse.

M…: The moment you presuppose anything, one has abandoned knowledge. Thus, if you are claiming anything on the basis of a presupposition, the claim(s) that follow are also likewise tainted.

Jimmy Stephens: Why’s that?

bait: It’s because assumptions are not a pathway to knowledge. Epistemology 101: you can’t assume the truth. Presuppositions are a type of assumption.

Jimmy Stephens: That’s not what I meant by presupposition, so that’s missing the point. I agree assumptions are not a sufficient basis for knowledge. Since that’s all atheism has to offer, that’s why I’m not one.