The Critique of 'The Critique of Pure Reason' II: Preface to the Second Edition

In this post I'll note some areas of concern I have from an Aristotelian-Thomistic (henceforth just 'Aristotelian') point of view with Kant's B-edition preface. Again, as I said in my first post, this isn't really meant to be a summary of Kant's views, but more along the lines of a set of notes.

One thing which already indicates Kant has a different conception of reality than an Aristotelian realist view is his description of logic toward the beginning. Kant says that logic is "the science that exhaustively presents and strictly proves nothing but the formal rules of all thinking." But a realist will want to ask why logic is defined in terms of its applicability to our thoughts rather than to mind-independent propositions or even objects. After all, since Kant's time, many different logics have been developed, and we can think in terms of any of these if we want to. But this says nothing about which one more correctly describes reality. Of course, what Kant will want to argue is that what I am calling "reality" is actually a product of human cognitive capacities. So the difference to note here between the two views is not so much of whether logic is to be applied to reality, but rather, what reality refers to.

A second point of interest is Kant's discussion of mathematical knowledge at Bxii, where he takes as his example that of a Euclidean triangle. Kant uses this point to illustrate how he thinks it is that we acquire mathematical knowledge. What I would focus on though is his view that, more generally, Euclidean geometry is necessary. For Kant, a judgment is necessary if and only if it is a priori. The problem is that we now know that Euclidean geometry is not, in fact, necessary, since it doesn't even accurately describe the physical universe. So either euclidean geometry is not a priori or Kant was wrong to include necessity as part of something's being a priori. But it seems rather clear euclidean geometry was formulated a priori if anything was. So it must follow that not all a priori cognitions are necessary. But this is okay for the Aristotelian. The Aristotelian method of doing metaphysics or science has never been equivalent to discovering necessary truths which are wholly a priori; rather, it is empirical. We can delineate what is metaphysically possible and impossible through a priori reasoning and we see whether our theories correspond to empirical reality.

Kant's view of the a priori goes with his view of metaphysics. He defines metaphysics as "a wholly isolated speculative cognition of reason that elevates itself entirely above all instruction from experience." Not according to an Aristotelian view however. As Aquinas states in 'De Veritate', "Whatever is in the intellect was first in the senses." Of course, the reason Kant wants to make metaphysics a wholly a priori discipline is because he wants the certainty which he thinks the method of previous thinkers cannot provide. In his own words Kant thinks that "up to now [i.e. up until Kant] the procedure of metaphysics has been a mere groping, and what is the worst, a groping among mere concepts." But the Aristotelian wants to ask why it has only been a "mere groping among concepts"? For one, the metaphysician does not need to limit the scope of his inquiry to concepts, at least if we don't hold to the view that metaphysics must be a priori. As regards "mere groping," admittedly, we cannot be absolutely certain our metaphysical theories are true; but this is a far too strict condition upon knowledge which, were it not for Descartes, we would not think was necessary.

In the next post I will focus on the second half of the preface, examining Kant's solution to the problem of metaphysical knowledge as he sees it.

Is Nihilism Self-Refuting?

Woo, been a while since a post. Okay. Consider the following argument, contra moral nihilism, i.e. the view that nothing is moral or immoral:

(1) If a belief is true, then we ought to believe it.
(2) Nihilism is a belief.
So, (3) If nihilism is true, then we ought to believe it.
(4) It is not the case that we ought to believe nihilism.
Therefore, (5) Nihilism is not true.

Is there something to 1 such that, if a nihilist were to deny it, he would be leading himself to irrationality? It would seem so. The denial of 1 is, after all, "It is not the case that if a belief is true, we ought to believe it." This seems to almost undercut the entire idea of rational argument. Denying 1 would also mean that it's not the case that, if nihilism were true, then we ought to believe it. Maybe they're fine with that, but I'm sure as heck not becoming a moral nihilist if I don't have any obligation to.

The nihilist seems to be committed to 4, since any "oughts" related to things like intellectual virtue or intellectual honesty are false on nihilism; these are, after all, ethical ideas (honesty is a virtue).

Maybe the nihilist could find some way of understanding "ought" which is entirely unrelated to ethics, making it possible to affirm that if a belief is true, then we ought to believe it, along with an obligation to believe nihilism. All of this without committing to the truth of any moral theses. This already seems implausible as such. Questions of epistemic justification, intellectual responsibility, and warrant are probably inseparable from ethics in some way. Nevertheless, suppose the nihilists pull it off. This leads to there being at least some normativity and responsibility, and the possibility of normativity and obligation in one sphere makes it harder to see why the nihilist would deny normativity and obligation in the sphere of ethics.

The situation looks grim for the nihilist then. They can (A) deny 1, implying that we're free to believe whatever we please (including the falsity of nihilism), as well as making the whole project of rational argumentation dubitable, or (B) deny 4 and accept that there is some normativity and obligation, putting them at odds with their claims about ethics. Or maybe they'll come to terms and accept all our premises. :-)

That's all a little sloppy I think, but I hope it makes sense. If not, please tell me.
P.S., birthday in two days! Would be a nice birthday present if I could figure out the soundness of this argument.

Does Conceivability Entail Possibility?

The following should probably be pretty clear to some people. Just another way of showing that conceivability does not imply possibility. The proof will go somewhat informally with a few hidden premises, and I'm not even sure if it's any good.

Suppose
(1) If I can conceive of a possible world, then such a world exists. (This doesn't mean it's actual of course.)
Further,
(2) I can conceive of a possible world which is empty.
(3) Therefore, there is an empty possible world.
(4) I can conceive of a necessary being.
One can easily deduce from (4) that
(5) Therefore, there is no empty possible world.
(6) Therefore, there is an empty possible world and there is no empty possible world.
(7) Therefore, ~(1). (because 1 implies a contradiction, viz. 6)

By "empty possible world" I mean a world in which no entities exist. Some may object that this is harder to understand than at first sight, and may in fact be inconceivable. For those who agree that it is conceivable we've shown that (1) is false. For the skeptic's sake let's take a less controversial example. Let's say that in every possible world there exists at least one entity. This isn't to say that in each world it is the same entity, i.e. we're not saying there exists something x such that x exists in all possible worlds. To illustrate the point let's use a little bit of basic sets. Take two sets A = {1,2} and  B = {3,4). These two sets are disjoint. If you tried to find a set which has as its elements/members all x such that x is in A and x is in B you'd come up with an empty set. In other words, they have no members in common. In an analogous way we can conceive of two possible worlds being "disjoint", that is, not having any entities in common. So we can say

(8) I can conceive of two "disjoint" possible worlds.
(9) Therefore, there are two disjoint possible worlds.

Remember, this is consistent with our rejection of (2).

(10) If there are two disjoint possible worlds, then there are no entities common to all possible worlds.
(11) Therefore, there are no entities common to all possible worlds
(12) If a necessary being is possible, then there are some entities which are common to all possible worlds.
(13) Therefore, there are some entities common to all possible worlds. (One could easily show that this follows.)

We've of course come to our flat contradiction with (11) and (13) and shown (1) to be false.

Without (1) how can we learn about metaphysical possibility? It seems to me that we'll have to go back to those good ol' essences, thus raising the further question of how we can know both essences and their implications. I wonder though how we can figure out why anything exists at all. We can't turn to essences to learn about the modal properties of being. Being has no "essence", since it's a transcendental. The falsity of (1) also has implications for those who want to create modal arguments for God. We can't just go based on God's conceivability. It's interesting to note that Robert Maydole's proof of the Maximally Great Being's (MBG) metaphysical possibility seems to rely on the very essence of the MGB.

P.S. Now we've got Ss. Augustine, Anselm, and Bonaventure praying for us on the side. :-)