Last week I was listening to a lecture by Daniel Robinson on Kant’s first Critique that the Oxford philosophy department has made available online. It was the fourth part of a series of eight lectures Robinson gave on the Critique and it dealt with Kant’s treatment of the possibility of synthetic a priori propositions.
As we know, Kant denies that the lawfulness of the world that we experience is conveyed to us by the appearances of things. This lawfulness is something that the mind itself imposes upon appearances. This is Kant 101.
But I was struck by what seems to me to be Robinson’s very un-Kantian way of explaining this doctrine to his audience. This is how Robinson put it in the lecture:
The very laws of the objective sciences show those sciences to have a rational character. Now that lawfulness is not given in the appearances. The stimulus that arrives at the organs of sense does not carry any information regarding lawfulness with it. If it’s visual, it’s just photons. If it’s auditory, it’s just air vibrations. So, the lawfulness must be coming from some place other than the arriving wave of stimulation.
This exact statement obviously could not have been made by Kant since photons were not “discovered” until the 20th century. But that’s not the part of the explanation that I find puzzling. Robinson is claiming to know much more about what is affecting our sense organs than I believe Kant would allow.
Following the Transcendental Aesthetic in the Critique Kant adds these remarks to clarify what his claims are (so far) about the possibilities and limits of human knowledge:
In order to prevent any misunderstanding, it will be requisite, in the first place, to recapitulate, as clearly as possible, what our opinion is with respect to the fundamental nature of our sensuous cognition in general. We have intended, then, to say that all our intuition is nothing but the representation of phenomena; that the things which we intuit, are not in themselves the same as our representations of them in intuition, nor are their relations in themselves so constituted as they appear to us; and that if we take away the subject, or even only the subjective constitution of our senses in general, then not only the nature and relations of objects in space and time, but even space and time themselves disappear; and that these, as phenomena, cannot exist in themselves, but only in us. What may be the nature of objects considered as things in themselves and without reference to the receptivity of our sensibility is quite unknown to us. We know nothing more than our mode of perceiving them, which is peculiar to us, and which, though not of necessity pertaining to every animated, is so to the whole human race. With this alone we have to do (A41-42/B59-60).
These remarks, of course, come before the Transcendental Analytic, the Transcendental Dialectic, etc., so we do not yet have Kant’s complete epistemology as it is worked out in the Critique. Nevertheless, nothing that he says later on will alter what he says above and the above remarks are all we need to see how strange Robinson’s explanation of Kant is.
Robinson says that we cannot get any lawfulness out of what we see or hear because what is affecting our eyeballs is just photons and what is affecting our ears is just air vibrations. Well, if Robinson knows what’s affecting our eyes and ears, Kant would probably like to know where Robinson is getting his information. Evidently Robinson is drawing on the conclusions of the natural sciences and assuming that they are right about what’s behind visual and auditory stimulus. But these sciences are basing their conclusions on observation of phenomena either directly or by means of instruments. Yet, Kant tells us that phenomena convey nothing about the things themselves. At best, then, we can merely say that “something” is affecting our eyes and ears but to say that this is photons or air waves seems to go further than Kant permits.
Indeed, Robinson is free to disagree with Kant about this (and I think he should). But then he would not be presenting Kant’s Critique of Pure Reason but Robinson’s Critique of Pure Reason.