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 the expression of the forms of thought, as it is the task of logic to teach the operations with the forms of thought themselves.