Self-Consciousness and Objects


Immanuel Kant's ``Transcendental deduction of the pure concepts of the understanding'' is usually considered to be one of the most important parts of his Critique of Pure Reason. Among other things, we find in the Deduction an exposition of Kant's theory of self. He ties together here the possibility of self-consciousness and the possibility of knowledge of objects. In particular, he argues that we can have objects only because of the ``synthetic [transcendental] unity'' of the ``pure apperception''. However, this unity arises through the unity of the manifold of sensibility; hence, the intuitions underlying the objects are themselves necessary for self-consciousness. However, because the manifold of sensibility is distinguished from the objects formed therefrom, Kant's idea of self-consciousness is a well-founded concept, and not the result of a vicious circle of definitions.

Note: The Deduction was completely rewritten in the B edition of the Critique: here we concern ourselves only with the version appearing the the B edition. The translation referred to is that by Paul Guyer and Allen W. Wood (Cambridge Press).

The argument

Synthesis of the manifold

The transcendental deduction begins with §15, ``On the possibility of a combination in general'' (B129). A combination, argues Kant, is never given us, but is rather constructed by the spontaneity of representation---that is, of understanding. Kant names this combination synthesis; it is unique in that it is not given through objects, but rather is ``executed only by the subject itself'' (B130). In addition, analysis must always be preceded by this synthesis: for, without synthesis, there is nothing to analyse or take apart (or, as Kant puts it, ``dissolve'').

The first important step in the deduction follows: that the concept of combination also carries with itself the concept of the unity of the manifold. Thus the unity of the manifold does not arise from combination, but is rather presupposed by it. Because the category of unity (§10, B106) is based on a function of judgement, and hence of combination, the unity of the manifold cannot be the logically subsequent category of unity. The unity of the manifold, as will be claimed in §17, grounds the possibility of understanding.

The ``I think'' and pure apperception

In §16 (B131), Kant introduces the ``I think''. For Kant, this is not a Cartesian substance, or any kind of thing, but rather a determination or judgement. Kant claims, in the second important step of the deduction, that ``the I think must be able to accompany all my representations''. That is, every representation of mine must be such that I can say ``I have this representation'' or ``I think this''. Were this not the case, the representation could not be thought, and would thus not be a representation at all. In the case of representations of the understanding, this is unproblematic: since such representations are created by thinking, the ``I think'' is attached to them at their creation. However, in intuitions representation precedes thought; thus there must be some other relation between the manifold of intuitions and the ``I think''. This relation, the representation of the ``I think'' in intuition, is ``an act of spontaneity'' (B132), and thus not part of passive sensibility. Kant labels this representation ``pure apperception'' (or ``original apperception''). It is pure (that is, a priori) because, accompanying all representation, it cannot rely on experience. The unity of this pure apperception Kant labels the transcendental, or synthetic, unity of self-consciousness.

The unity that Kant claims here is very important. In §17 (see below), Kant shows that this unity of self-consciousness is a necessary condition for the possibility of understanding. In contrast, the empirical self-consciousness is ``dispersed''; it is added to representations rather than being a fundamental part of them. This is why the analytic unity of apperception depends on the synthetic unity: we are able to determine (via a ``mark'') that our representations belong to a single self only because those representations are already joined by the synthetic unity of pure apperception.

The unity of consciousness as necessary for understanding

One of the most important epistemological claims of the Deduction (or, for that matter, of the entire Critique) appears in §17. In the Transcendental Aesthetic, Kant demonstrated that space and time are the conditions for sensible intuition; this was the supreme principle of intuition with respect to sensibility. In this section, Kant claims that the synthetic unity of apperception serves a similar rôle, as the supreme condition for intuition with respect to the understanding. An object, Kant argues, is ``that in which the manifold of a given intuition is united''. This unification, of course, presupposes a unity of consciousness which would allow their synthesis. Since the manifold is united in one consciousness, the synthetic unity of apperception is not only necessary to cognize an object: it is in fact necessary for intuitions to become objects at all. Thus, without the pure apperception and its unity, we could have neither objects not understanding.


In §18, Kant attempts to demonstrate the objectivity of the transcendental unity. According to this section, it is through the transcendental unity that a manifold becomes a concept of the object. Thus the transcendental unity is objective; this is opposed to the subjective unity of consciousness, which Kant calls a ``determination of inner sense'' (B139). Since the subjective unity is empirical, it is ``entirely contingent''. However, since the subjective unity is an inner intuition, it must rest on the original, transcendental, unity.

§19 demonstrates that the form of judgements also require an objective unity. For, if there were not one, a claimed relation could not be objectively valid (and hence not a judgement). To use Kant's example, without an objective unity of apperception, I could say only ``I feel pressure when I carry this body'', not ``This body is heavy''. Thus, without an objective unity, I could not join two representations in an object, but only in myself (and hence without any objective validity).

The remainder of the Deduction

In the remainder of the deduction, Kant proceeds further. In §20, he demonstrates that the categories necessarily link the manifold of representation to apperception. In §§22-23, the use of the categories is limited to objects of possible experience. These sections are beyond the scope of this essay; they are not as important as the others to understanding the fundamental relationship between objects and self-consciousness. §24 and §25 are somewhat more relevant: they differentiate between pure apperception, with which we represent only that we exist, and inner sense, in which we represent ourself as we appear. Thus, in §24, Kant is careful to distinguish the I that thinks (the transcendental I of pure apperception) from the I that intuits itself (the empirical I of inner sense). Though these selves are different, they are ``identical . . . as the same subject'' (B155). Because I am an object for myself, pure apperception must also pertain to the intuition of myself (since objects, as demonstrated in §17, presuppose the unity of apperception). Very importantly, Kant argues that we are conscious of our self (i.e. its existence), but that we cannot know the self (B158).

The success of the argument

Kant's idea of the self and self-consciousness may be summarized in a few basic points:

  1. We are conscious, through the transcendental unity of apperception, of a self.
  2. The self given by the transcendental unity of apperception is neither an appearance nor a thing in itself (B158). That is, we know something exists, but not what that something is.
  3. Intuitions can become objects for us only through the transcendental unity of apperception. Thus the unity is a necessary condition of our understanding, in much the same way that space and time are necessary conditions of our sensibility.

Transcendental unity of apperception

As for the first point, Kant seems to prove only part of what is required. There is certainly something uniting our representations, and we certainly must be able to say of our representations ``I think this''; in this respect there is nothing in the Deduction with which to argue. What requires proof, however, is that this ``I'' is transcendental---that is, free of empirical content. Kant seems to handle this well: since intuitions precede thought, they must somehow have an a priori connection to the ``I think''; this connection is precisely the pure apperception. However, this part of the argument turns on the distinction between intuition and thought. This distinction certainly requires a defence that Kant does not attempt to give.

In addition, Kant's argument for the unity of apperception assumes that the ``I think'' that we can accompany with our representations always refers to the same ``I''; if not, there is not necessarily an a priori connexion, as a new ``I think'' may be constructed for each representation (in fact, for each reflection upon each representation). Kant's proof only holds if we can simultaneously claim ``I think'' of all our representations: otherwise, there is no reason to assume that the I remains the same.

Kant's other argument for the transcendental unity of apperception is even shakier. He says that, without the synthetic unity of apperception, ``I would have as multicolored, diverse a self as I have representations of which I am conscious'' (B134). This seems to be a petitio principii: Hume's claim is that the self, inasmuch as it exists, is ``multicolored'' and ``diverse'' precisely because it comprises ``the representations of which I am conscious''.

The nature of the self

The second claim is somewhat strange. Kant, in demonstrating that there exists a transcendental self, runs into a problem: what is it? Clearly, if the self can be demonstrated by transcendental apperception, it cannot be an appearance. However, it is a fundamental tenet of transcendental idealism that we can have no knowledge of things in themselves. Hence, Kant is forced to claim that we cannot know this self at all. We do, however, according to §24, have knowledge of an appearance, namely self-intuiting inner sense. There are thus two selves: the transcendental self, demonstrated by the unity of apperception, and the empirical self of inner sense. Somehow, they refer to ``the same subject'' (B155), but Kant does not explain this statement, especially the question this new phrasing introduces: what precisely is a subject if not the self? Kant's equivocation and lack of clarity indicate that, even through the complete rewrite of the Deduction, he was still not sure of the standing of the self with respect to transcendental idealism.

Objects and the self

The problem in the last of the three points lies partly in the use of the word ``object'' (Object here, not Gegenstand). Kant defines an object as ``that in the concept of which the manifold of a given intuition is united'' (B137). This is the first appearance in the Critique of this or any similar definition of ``object''. Kant, I think, has not demonstrated at all that such a definition is coherent, or at least that it refers to something that actually exists (even subjectively).

Even assuming that these ``objects'' exist, there is another problem with the proof. According to §15, all combination and unity presupposes the unity of consciousness; thus, Kant would say, that unity of consciousness indeed necessary for the existence of objects. However, as discussed above, §15 may be incorrect. Thus, if Kant is wrong there, the claim about existence of objects has no grounds on which to stand.


Kant's case for the existence of the self as the transcendental unity of pure apperception is certainly not airtight. However, the holes in the argument are not necessarily fundamentally damaging to Kant's position. We have not disproved Kant's claims on the nature of the self and the relation of self-knowledge to knowledge of objects. Rather, we have shown that Kant did not always adequately defend (or, in some cases, clearly express) his position. A Humean would certainly be able to maintain the ``bundle'' theory of self against Kant, though it is not clear that either theory would be demonstrably better.

More importantly, though, Kant seems to create two or three selves: the unknowable self of pure apperception; the empirical self that appears to us through inner sense; and the ``subject'' to which both of these are ``identical''. While it may be true that all three things are the same, such an identity is, according to transcendental idealism, undemonstrable. Of what use is a self with no knowable properties? How, indeed, can it even be called a ``self''?

--Neil Moore

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