I introduced what I called the “Kantian error” in an earlier post, and have since used it in explaining several issues such the understanding of unity and the nature of form. However, considering my original point, we can see that there are actually two relevant errors.
First, there is the Kantian error itself, which amounts to the claim that nothing real can be truly known.
Second, there is an anti-Kantian error, namely the error opposed to the element of truth in Kant’s position. I pointed out that Kant is correct that we cannot know things “as they are in themselves” if this is meant to identify the mode of knowing and the mode of being as such. The opposite error, therefore, would be to say that we can know things by having a mode of knowing which is completely identical to the mode of being which things have. Edward Feser, for example, effectively falls into this error in his remarks on sensible colors discussed in an earlier post on truth in the senses, and more recently at his blog he reaffirms the same position:
Part of the reason the mechanical conception of matter entails the possibility of zombies is that it takes matter to be devoid of anything like color, sound, taste, odor, heat, cold and the like, as common sense conceives of these qualities. On the mechanical conception, if you redefine redness (for example) as a tendency to absorb certain wavelengths of light and reflect others, then you can say that redness is a real feature of the physical world. But if by “redness” you mean what common sense understands by it – the way red looks in conscious experience – then, according to the mechanical conception, nothing like that really exists in matter. And something similar holds of other sensory qualities. The implication is that matter is devoid of any of the features that make it the case that there is “something it is like” to have a conscious experience, and thus is devoid of consciousness itself.
The implication here is that the way red looks is the way a red thing is. Since the emphasis is in the original, it is reasonable to take this to be identifying the mode of the senses with the mode of being. In reality, as we said in the earlier discussion, there is no “redefinition” because the senses do not define anything in the first place.
Both mistakes, namely both the Kantian and anti-Kantian errors, imply contradictions. The claim that there is something that we cannot know in any way contradicts itself, since it implies that we know of something of which we know nothing. Thus, it implies that an unknown thing is known. Similarly, the claim that the mode of knowing as such is the same as the mode of being, to put it in Kant’s words, “is as much as to imagine that experience is also real without experience.” In other words, suppose that “the way red looks” is the very way a red apple is apart from the senses: then the apple looks a certain way, even when no one is looking, and thus precisely when it does not look any way at all.
Thus both errors imply similar contradictions: an unknown thing as such is known, or a known thing as such is unknown. The errors are generated in much the way Kant himself seems to have fallen into the error. Either knowledge is possible or it is not, we say. If it is not, then you have the Kantian error, and if it is, it appears that our way of knowing must the same as the way things are, and thus you have the anti-Kantian error.
As I pointed out in discussing consistency, an inconsistent claim, understood as such, does not propose to us any particular way to understand the world. The situation described is unintelligible, and in no way tells us what we should expect to find if it turns out to be the case. Given this fact, together with the similarity of the implied contradictions, we should not be surprised if people rarely double down completely on one error or the other, but rather waver vaguely between the two as they see the unpalatable implications of one side or the other.
Thus, the problem arises from the false dichotomy between “knowledge is not possible” and “knowledge is possible but must work in this particular way, namely by an identity of the mode of knowing and the mode of being.” I said in the linked post that this is “one of the most basic causes of human error,” but it might be possible to go further and suggest that it is the principal cause of philosophical error apart from error caused by trading truth for other things. At any rate, the reader is advised to keep this in mind as a distinct possibility. We may see additional relevant evidence as time goes on.