In rational psychology the “I think” is taken in its universal, or to use Kant’s somewhat misleading term, problematic aspect, that is to say, not as a judgment expressive of the self’s own existence but “in its mere possibility,”[1413] as representing the self-consciousness of all possible thinking beings. As we cannot gain a representation of thinking beings through outer experience, we are constrained to think them in terms of our own self-consciousness. The “I think” is thus taken as a universal judgment, expressing what belongs to the conception of thinking being in general. The judgment is so interpreted by rational psychology, “in order to see what predicates applicable to its subject (be that subject actually existent or not) may flow from so simple a judgment.”

In summarising what is directly relevant in the argument of the transcendental deduction, Kant emphasises that the I, as representation, is altogether empty of content.[1414]

“We cannot even say that it is a conception, but only that it is a bare (blosses) consciousness which accompanies all conceptions. Through this I or he or it (the thing) which thinks, nothing further is represented than a transcendental subject of the thoughts = x....”

It is apprehended only in its relation to the thoughts which are its predicates; apart from them we cannot form any conception whatever of it, but can only revolve in a perpetual circle, since any judgment upon it has already made use of its representation.[1415]

The patchwork character of the Critique, the artificial nature of the connections between its various parts, is nowhere more evident than in this section on the Paralogisms. According to the definition given of transcendental illusion, we naturally expect Kant’s argument to show that the Paralogisms rest upon a failure to distinguish between appearance and reality. As a matter of fact, the cause of their fallacy is traced in the first three Paralogisms solely to a failure to distinguish between the logical and the real application of the categories. The argument can indeed be restated so as to agree with the introductory sections of the Dialectic. But Kant’s manner of expounding the Paralogisms shows that this chapter must originally have been written independently of any intention to develop such teaching as that of the sections which in the ultimate arrangement of the Critique are made to lead up to it.[1416]

First Paralogism: of Substantiality.[1417]—Save for the phrase ‘subject in itself,’ there is, in Kant’s comment upon this Paralogism, not a word regarding the necessity of a distinction between appearance and reality, but only an insistence that the “I think” yields no knowledge of the thinking self. Consciousness of the self and knowledge of its underlying substance are by no means identical. The self, so far as it enters into consciousness, is a merely logical subject; the underlying substrate is that to which this self-consciousness and all other thoughts are due. It is in the light of this distinction that Kant discusses the substantiality of the subject. As expressive of the “I think,” the category of substance and attribute can be employed only to define the relation in which consciousness stands to its thoughts; it expresses the merely logical relation of a subject to its predicates. It tells us nothing regarding the nature of the “I,” save only that it is the invariable centre of reference for all thoughts. In order to know the self as substance, and so as capable of persisting throughout all change, and as surviving even the death of the body, we should require to have an intuition of it, and of such intuition there is not the slightest trace in the “I think.” It “signifies a substance only in Idea, not in reality.”[1418] As Kant adds later,[1419] the permanence and self-identity of the representation of the self justifies no argument to the permanence and self-identity of its underlying conditions. Inference from the nature of representation to the nature of the object represented is entirely illegitimate. In the equating of the two, and not, as the introduction to the Dialectic would lead us to expect, in a failure to distinguish appearance from reality, consists the paralogistic fallacy of this first syllogism.

Second Paralogism: of Simplicity.[1420]—We may follow Adickes[1421] in his analysis of A 351-62. (a) The original criticism, parallel to that of the first Paralogism, would seem to be contained in paragraphs five to nine. (b) The opening paragraphs, and (c) the concluding paragraphs, would seem, for reasons stated below, to be independent and later additions.

(a) The argument of the central paragraphs runs almost exactly parallel with the criticism of the first Paralogism, applying the same line of thought, in disproof of the assumed argument for the simplicity of the soul. It may be noted, in passing, that Kant here departs from his table of categories. There is no category of simplicity. The connection which he seeks to establish between the concept of simplicity and the categories of quality is arbitrary. It more naturally connects with the category of unity; but the category of unity is required for the third Paralogism. For explanation of the way in which he equates the concept of simplicity with the category of reality Kant is satisfied to refer the reader to the section on the second antinomy in which this same identification occurs.[1422] Indeed the simplicity here dwelt upon seems hardly distinguishable from substantiality, and therefore it is not surprising that Kant’s criticism of the second Paralogism should be practically identical with that of the first.[1423] Since the “I,” as logical subject of thought, signifies only a something in general, and embodies no insight into the constitution of this something, it is for that reason empty of all content, and consequently simple. “The simplicity of the representation of a subject is not eo ipso a knowledge of the simplicity of the subject itself....” The second Paralogism thus, in Kant’s view, falsely argues from the merely logical unity of the subject in representation to the actual simplicity of the subject in itself.

(b) One reason for regarding the first four paragraphs as a later addition is their opening reference to the introductory sections of the Dialectic, of which this chapter otherwise takes little or no account. This Paralogism is, Kant declares, “the Achilles of all the dialectical inferences in the pure doctrine of the soul,” meaning that it may well seem a quite invulnerable argument.[1424]