Here follows a note on Kant’s Critique of Pure Reason. Thereafter a reflection on the state of contemporary physics. I am under-qualified on both counts, but feel sufficiently strongly to have a go at conceptual clarification anyway.
Kant had a searching question. Given that such and such a state holds, what conditions must be satisfied in order for this to be the case? Directing this question to the external world (Newton, Galileo), he conducted an examination of the human faculties which enable knowledge. After an arduous journey the result was his description of the Transcendental Unity of Apperception. Roughly speaking this is the ‘I think’ which accompanies all contents of consciousness, and serves to identify each person’s thoughts as belonging to that person’s consciousness. Their synthetic unity need not be regarded as perfect, although, as pre-eminently in the case of Kant, it can be laboured over. The ‘I think’ cannot be analysed further, and in this sense is transcendental, or what we would call today ‘a limit concept’. A minimum requirement of having experiences at all is a combining of intuition and concepts (roughly speaking sensibility and thoughts). Intuition is achieved through the senses and fortified by the imagination, both recollective and productive. Concepts are derived from the imaginative reflection on the forms and contents of experience. Objects are given us through sensibility, then thought by the understanding. Sensibility is receptive but nevertheless has a priori elements, namely time and space, without which experience would not be possible at all. (Einstein’s discoveries, confirmed empirically, leave Kant’s theory of the a priori nature of time and space enormously compromised if not refuted.) The deduction of the categories of understanding was achieved by the faculty of judgement, which brought into agreement the representation of things and the a priori concepts of the understanding. Kant’s famous summing up is: ‘Thoughts without content are empty, intuition without concepts are blind.’
A word more about apperception. Empirical apperception is consciousness of self according to determination afforded by our inner state of perception. The sense of self is fairly dim. (Arguably Heidegger exploited this point in his notion of being-in-the-world). The transcendental unity has the faculty of making one’s own representations the objects of one’s thoughts. That is to say that we have the power to reflect and exercise self-criticism.
This, for me, is one of the greatest feats of intellectual enquiry I have ever encountered. It explains with great power why there must be an a priori element in human knowledge. It is, if you like, a reasoned and articulated account of human finitude. The synthesising ability of the ‘I’, the transcendental subject forms the vehicle of every experience.
Here are four words from the vocabulary of modern physics. Relativity, observer, measurement, uncertainty. All these words in ordinary usage have a psychological colouring. This shrinks in their technical usage in physics. For thoroughgoing materialists there is no problem, a bottom-up description of reality will capture everything that can be captured. Consciousness will be neuronal behaviour. However as C.S. Peirce knew, measurement is a triadic relationship. Something is compared with something else and what does the comparing is mental or intentional. Measurement has meaning. In the words of the song ‘ There may be trouble ahead.’ Consciousness has been downgraded in modern physics, but there are signs of the ‘return of the repressed’.