(3.) These real, unalterable, original forms of thought are certainly those of Kant's logical table of judgments; only that in this table are to be found blind windows for the sake of symmetry and the table of the categories; these must all be omitted, and also a false arrangement. Thus:—
(a.) Quality: affirmation and negation, i.e., combination and separation of concepts: two forms. It depends on the copula.
(b.) Quantity: the subject-concept is taken either in [pg 088] whole or in part: totality or multiplicity. To the first belong also individual subjects: Socrates means “all Socrateses.” Thus two forms. It depends on the subject.
(c.) Modality: has really three forms. It determines the quality as necessary, actual, or contingent. It consequently depends also on the copula.
These three forms of thought spring from the laws of thought of contradiction and identity. But from the principle of sufficient reason and the law of excluded middle springs—
(d.) Relation. It only appears if we judge concerning completed judgments, and can only consist in this, that it either asserts the dependence of one judgment upon another (also in the plurality of both), and therefore combines them in the hypothetical proposition; or else asserts that judgments exclude each other, and therefore separates them in the disjunctive proposition. It depends on the copula, which here separates or combines the completed judgments.
The parts of speech and grammatical forms are ways of expressing the three constituent parts of the judgment, the subject, the predicate, and the copula, and also of the possible relations of these; thus of the forms of thought just enumerated, and the fuller determinations and modifications of these. Substantive, adjective, and verb are therefore essential fundamental constituent elements of language in general; therefore they must be found in all languages. Yet it is possible to conceive a language in which adjective and verb would always be fused together, as is sometimes the case in all languages. Provisionally it may be said, for the expression of the subject are intended the substantive, the article, and the pronoun; for the expression of the predicate, the adjective, the adverb, and the preposition; for the expression of the copula, the verb, which, however, with the exception of the verb to be, also contains the predicate. It is the task of the philosophy of grammar to teach the precise mechanism of [pg 089] the expression of the forms of thought, as it is the task of logic to teach the operations with the forms of thought themselves.
Note.—As a warning against a false path and to illustrate the above, I mention S. Stern's “Vorläufige Grundlage zur Sprachphilosophie,” 1835, which is an utterly abortive attempt to construct the categories out of the grammatical forms. He has entirely confused thought with perception, and therefore, instead of the categories of thought, he has tried to deduce the supposed categories of perception from the grammatical forms, and consequently has placed the grammatical forms in direct relation to perception. He is involved in the great error that language is immediately related to perception, instead of being directly related only to thought as such, thus to the abstract concepts, and only by means of these to perception, to which they, however, have a relation which introduces an entire change of the form. What exists in perception, thus also the relations which proceed from time and space, certainly becomes an object of thought; thus there must also be forms of speech to express it, yet always merely in the abstract, as concepts. Concepts are always the primary material of thought, and the forms of logic are always related to these, never directly to perception. Perception always determines only the material, never the formal truth of the proposition, for the formal truth is determined according to the logical rules alone.
I return to the Kantian philosophy, and come now to the Transcendental Dialectic. Kant opens it with the explanation of reason, the faculty which is to play the principal part in it, for hitherto only sensibility and understanding were on the scene. When considering his different explanations of reason, I have already spoken above of the explanation he gives here that “it is the [pg 090] faculty of principles.” It is now taught here that all the a priori knowledge hitherto considered, which makes pure mathematics and pure natural science possible, affords only rules, and no principles; because it proceeds from perceptions and forms of knowledge, and not from mere conceptions, which is demanded if it is to be called a principle. Such a principle must accordingly be knowledge from pure conceptions and yet synthetical. But this is absolutely impossible. From pure conceptions nothing but analytical propositions can ever proceed. If conceptions are to be synthetically and yet a priori combined, this combination must necessarily be accomplished by some third thing, through a pure perception of the formal possibility of experience, just as synthetic judgments a posteriori are brought about through empirical perception; consequently a synthetic proposition a priori can never proceed from pure conceptions. In general, however, we are a priori conscious of nothing more than the principle of sufficient reason in its different forms, and therefore no other synthetic judgments a priori are possible than those which proceed from that which receives its content from that principle.