This is the real reason why, however perfect rigorous concepts become, conceptual fictions remain ineliminable, and indeed obtain from these fresh nourishment. They cannot be criticized and resolved by means of rigorous concepts, because they are of a different order from them: they cannot act as inferior degrees of the rigorous concept, because they presuppose it. The reason, which we were pledged to give, is given; and henceforward there can no longer arise any misunderstanding as to the relation of the concept to conceptual fictions. It is a relation not of identity, nor of contrariety, but simply of diversity. [Sidenote: _Pure concepts and pseudoconcepts._] The terminological question remains, and this, as always, has but slight importance. "Conceptual fictions" is a manner of speech; and no one would wish to combat manners of speech. For brevity's sake we shall call them _pseudoconcepts,_ and for the sake of clearness we shall call the true and proper concepts _pure concepts._ This term seems to us more suitable than that of _ideas_ (pure concepts), as opposed to _logical concepts_ (pseudoconcepts), as they were at one time called in the schools. It must further be noted, that the pseudoconcepts, although the word "concept" forms part of their name, are not concepts, they do not form a species of, nor do they compete with, concepts (save when forcibly made to do so); and that the pure concepts have not got the impure concepts at their side, for these are not truly concepts. Every word offers, in some degree, a hold for misunderstanding, because it circulates in this base world, which is full of snares; the search for words which should absolutely prevent misunderstandings is vain, for it would be necessary first of all to clip the wings of the human spirit. We may prefer one word to another, according to historical contingencies; and for our part we prefer the words _pseudoconcept_ and _pure concept,_ if for no other reason than to remind the makers of fictional concepts to be modest, and to flash above their heads the light of the only true form of concept, which is logical nature itself in its universality and in its severity. How can we fail to think that the choice has been well made if this title of _pure concept_ please the few, but terrify the many and irritate the most, more than the red cloth shaken before the eyes of the bull; and if, like every efficacious medicine, it provoke a reaction in the organism of the patient? [Footnote 1: These relations are examined in the _Philosophy of the Practical,_ first part.] III THE CHARACTERISTICS AND THE CHARACTER OF THE CONCEPT The characteristics of the pure concept, or simply, concept, may be gathered from what has previously been said. [Sidenote: _Expressivity._]