Maimon's Critique of the Critique

Salomon Maimon offers a series of critiques of Kant’s Critique of Pure Reason in his Letters from Philaletes to Aenesidemus, in order to establish his skepticism. The most prevalent of theses is the critique of Kant’s idea of the “thing-in-itself.” For Kant, a thing in itself is outside the sphere of possible experience, yet is also the source of cognition. Maimon agreed with Kant that the thing in itself is beyond the sphere of possible experience, but holds that this does not mean that the thing in itself cannot be an object of cognition in principle. (http://plato.stanford.edu/archives/sum2009/entries/maimon)
Maimon looks at the relationship between logic and transcendental philosophy in the first part of his sixth letter, and claims that Kant inverts the two. While the logical forms are all that can be truly known, they “have no meaning at all when abstracted from their transcendental meaning.” (185, emphasis in original) One cannot give the meaning of logical affirmation and negation apart from the corresponding transcendental concepts of reality and negation. Maimon then goes on to argue that logical reality and negation presuppose the transcendental and absolute categories and “otherwise they would not have meaning at all.” (186) Logic must, therefore, have transcendental philosophy as its premise, rather than the other way around, as Kant has it.
Part of Maimon’s objection rises from his contention that the logical forms have not yet been subjected to proper scrutiny and have always just been assumed to be valid and complete, since they were proposed by Aristotle. “[The Critique of Reason] assumes [the logical forms]…even though without a previous critique they cannot be either correctly determined or complete in number, and cannot have either a meaning or a ground.” (186) So, to use the logical forms as a basis for transcendental philosophy would be to base that philosophy on an unproven foundation.
Even with his problems with the logical forms, Maimon still has problems accepting things in themselves as objective, as we see in the previous post. For Maimon, we cannot know anything objectively because we can only know our representations, not the things in themselves. If, as Maimon seems to believe, we cannot truly know things in themselves, but can only have perfect knowledge of pure thought, i.e. logic and math, then we seem to be on a slippery slope towards solipsism. For, if we cannot know anything objectively, but can only be sure of representations and pure thought, then how can we truly know that anything actually exists outside of our mind? This is, obviously, a position that one would not want to hold, but I think is one that could be drawn from Maimon’s skepticism.