In a Logic suitably reformed on this basis, this truth must first and foremost be proclaimed, and all its consequences deduced: the logical fact, _the only logical fact,_ is _the concept,_ the universal, the spirit that forms, and in so far as it forms, the universal. And if by induction be understood, as sometimes it has been, the formation of universals, and by deduction their verbal development, then it is clear that true Logic can be nothing but inductive Logic. But since by the word "deduction" has been more frequently understood the special processes of mathematics, and the word "induction" those of the natural sciences, it will be best to avoid both words and say that true Logic is Logic of the concept. The Logic of the concept, while employing a method which is both induction and deduction, will employ neither exclusively, that is, it will employ the speculative method which is intrinsic to it. The concept, the universal, considered abstractly in itself, is _inexpressible._ No word is proper to it. So true is this, that the logical concept remains always the same, notwithstanding the variation of verbal forms. In respect to the concept, expression is a simple _sign_ or _indication._ There must be an expression, it cannot be absent; but what it is to be, this or that, is determined by the historical and psychological conditions of the individual who is speaking. The quality of the expression is not deducible from the nature of the concept. There does not exist a true (logical) sense of words. The true sense of words is that which is conferred upon them on each occasion by the person forming a concept. [Sidenote: _Distinction between logical and non-logical judgements._] This being so, the only truly logical (that is, æsthetico-logical) propositions, the only rigorously logical judgements, must be those whose proper and sole content is the determination of a concept. These propositions or judgements are _definitions._ Science itself is nothing but a collection of definitions, unified in a supreme definition; a system of concepts, or highest concept. It is therefore necessary (at least as a preliminary) to exclude from Logic all those propositions which do not affirm universals. Narrative judgements, not less than those termed non-enunciative by Aristotle, such as the expression of desires, are not properly logical judgements. They are either purely æsthetic propositions or historical propositions. "Peter is passing; it is raining to-day; I am sleepy; I want to read": these and an infinity of propositions of the same kind are nothing but either a mere enclosing in words the impression of the fact that Peter is passing, of the falling rain, of my organism inclining to sleep, and of my will directed to reading, or an existential affirmation concerning those facts. They are expressions of the real or of the unreal, historical-imaginative or pure-imaginative; they are certainly not definitions of universals. [Sidenote: _Syllogistic._]