The Transcendental Deduction:
A Defense of the Objective Validity of the Categories of the Understanding

Kant takes up the defense of the objective validity of his ‘categories of the understanding’ in the very beginning of The Transcendental Analytic, laying out a ground for his thesis to stand on by shaping a kind of ‘transcendental self-consciousness’. This transcendental self-consciousness is a consciousness that is able to look down from above in self-reflection, a capability that allows it the creative spontaneity needed to synthesize its apprehensions and all the separate, jumbled sense data it receives. His argument actually centers around the fact that these apprehensions are initially separate, jumbled, and in need of an ordering framework of rules if they are to have any meaning at all in my experience. A priori concepts provide that framework, allowing for all the separate data to become intelligible parts of my experience. As he states, “The transcendental deduction of all a priori concepts therefore has a principle toward which the entire investigation must be directed, namely this: that they must be recognized as a priori conditions of the possibility of experiences (whether of the intuition that is encountered in them, or of the thinking).” (p.224-225).
Kant says that any object, if it is to be an object of my experience, must conform to the conditions of my experience, my knowledge-gaining capacities and limitations—and further, that these conditions are themselves pure, a priori concepts. In first setting out to show that there is a pure synthesis of apprehension, one that originates in the subject, Kant introduces the transcendental faculty of the imagination. He shows how it functions and why it is necessary as a bridge between sensory perception and the understanding, explaining its place within the original, transcendental unity of apperception. This transcendental unity is able to make a whole out of what the imagination reproduces, each piece being referenced back and gathered to a single entity.
Kant holds that cognition is impossible without the spontaneous reproductions of representations by the imagination, or (in other words) knowledge can’t come into being unless the imagination reconstructs for itself the manifold of available bits and pieces of raw sensory information it has received over time. We gather this information bit by bit as each present moment full of its own data passes into the next, becoming the past; without this faculty of the imagination allowing us to reproduce representations, the past sensory data we received would be lost to us and it wouldn’t be there for the transcendental self-consciousness (or ‘one’ consciousness) to incorporate into our present understanding, thus synthesizing a whole intelligible experience within the subject.
This transcendental faculty of the imagination is necessary for “even the purest and most fundamental representations of space and time [to] ever arise” (p.230). Take the example of a musical score. As it is played, we hear each note over a stretch of time, and each phrase over an even longer stretch of time. If we were only able to hold a single point of the music in our minds at any one point time however, lacking the imaginative faculty to reconstruct what had already gone by in order that they might be grouped together and connected into a whole, we would have no experience of music as we know it. No one momentary point of experience would ever remain with me to be made an intelligible part of my experience. Kant says that if,
“in counting, I forget that the units that now hover before my senses were successively added to each other by me, then I would not cognize the generation of a multitude through this successive addition of one to the other, and consequently I would not cognize the number; for this concept consists solely in the consciousness of this unity of the synthesis. The word “concept” itself could already lead us to this remark. For it is this one consciousness that unifies the manifold that has been successively intuited, and then also reproduced, into one representation” (p.230-231).

In examining the word concept and Kant’s use of it here, it becomes clear that it is a very important part of the deduction. Up to now he has been expounding on the necessity of the faculty of the imagination in order to pave the way to describe the transcendental self-consciousness and show that only with the collected data the imagination provides is it able to generate whole, understandable, and meaningful experience. He spends some time describing this ‘one consciousness’, and then grounds its ability to function in a priori concepts, showing that they are essential and absolutely necessary for the unification process to take place, and therefore for the fashioning of meaningful experience/ knowledge within the human mind.
In the end of the above quotation, he transitions into this description, saying “it is this one consciousness that unifies the manifold that has been successively intuited, and then also reproduced, into one representation” (p.231). And again, later on, it is
“that unity of consciousness that precedes all data of the intuitions, and in relation to which all representation of objects is alone possible. This pure, unchanging consciousness I will now name transcendental apperception… thus the original and necessary consciousness of the identity of oneself is at the same time a consciousness of an equally necessary unity of the synthesis of all appearances in accordance with concepts” (p.233, emphasis added).

The objects of my experience, as stated previously, in order to be such at all, must conform to the conditions inherent in the structure of my mind. “The unifying connection stems not from the object but from the subject, and (1) from a source of knowledge distinct from sensibility, which (2) is not receptive but itself active” (Höffe, p.76). This is classically Copernican— my experience originates within me, is shaped to my previous Being, and is created actively, rather than passively. This is achieved by making use of concepts as rules with which to unify and sculpt the gathered data into coherent wholes, the product of which action is the object of our experience. And hence, says Kant,

“concepts of objects in general lie at the ground of all experiential cognition as a priori conditions; consequently the objective validity of the categories, as a priori concepts, rests on the fact that through them alone is experience possible (as far as the form of thinking is concerned). For they then are related necessarily and a priori to objects of experience, since only by means of them can any object of experience be thought at all.” (p.224).

However, these concepts must be a priori in order to be used in this way, arising prior to experience. Otherwise they would have no authority from out of which to order experience. In this way it is made clear that Kant’s previously outlined ‘pure concepts of the understanding’ are necessary, bringing our everyday concepts into their most general, universal, and pure form: the categories of the understanding which make thought itself possible.
The categories make thought possible just as the pure concepts of space and time make intelligible experience (givenness) possible for me. Once one sees that the faculty of human understanding is essentially the same as the faculty of judgment, it becomes clearer why this is the case. With the pure concepts, we are able to have an initial grasp of certain properties and then move on to make judgments of the relationships existing between those properties (“the copula “is,” which combines subject and predicate into the unity of a judgement” (Höffe, p.79)), i.e., thinking. And the making of inferences comes naturally right behind that, and thus the development of knowledge.
Kant says that the categories necessarily apply and has proceeded, in this objective deduction, to defend his position. The central piece that one finds oneself returning to again and again to explain why the categories do necessarily apply, is that we only experience representations of things, not things-in-themselves, and therefore experience is self-referential. We actively experience by reproducing the representations that appear to us with the imagination, then unifying those collected representations in our transcendental self-consciousness. The central piece is clearly revolutionary in the Copernican sense: that the experience is to be mine. The fact that we must use the already-existing (pure) concepts of the understanding as a rule by which to extract meaning from (and, might I say, inflict order on?) that which we observe is due to this. The understanding is, according to Kant,
“not merely a faculty for making rules through the comparison of appearances; it is itself the legislation for nature, i.e., without understanding there would not be any nature at all, i.e. synthetic unity of the manifold of appearances, as such, cannot occur outside us, but exist only in our sensbility” (p.242).
Once again, in order for any object to be an object of my experience, it must conform to the conditions of my experience, my knowledge-gaining capacities and limitations—and further, these conditions are themselves pure, a priori concepts .

c. Mary Kathryn Gough, Sept. 2004