The venerability, reliability, and utility of truth is something which a person demonstrates for himself from the contrast with the liar, whom no one trusts and everyone excludes. As a "rational" being, he now places his behavior under the control of abstractions. He will no longer tolerate being carried away by sudden impressions, by intuitions.

We still do not yet know where the drive for truth comes from. For so far we have heard only of the duty which society imposes in order to exist: to be truthful means to employ the usual metaphors. Thus, to express it morally, this is the duty to lie according to a fixed convention, to lie with the herd and in a manner binding upon everyone. Now man of course forgets that this is the way things stand for him. Thus he lies in the manner indicated, unconsciously and in accordance with habits which are centuries' old; and precisely by means of this unconsciousness and forgetfulness he arrives at his sense of truth.

We obtain the concept, as we do the form, by overlooking what is individual and actual; whereas nature is acquainted with no forms and no concepts, and likewise with no species, but only with an X which remains inaccessible and undefinable for us.

Every word instantly becomes a concept precisely insofar as it is not supposed to serve as a reminder of the unique and entirely individual original experience to which it owes its origin; but rather, a word becomes a concept insofar as it simultaneously has to fit countless more or less similar cases which means, purely and simply, cases which are never equal and thus altogether unequal. Every concept arises from the equation of unequal things. Just as it is certain that one leaf is never totally the same as another, so it is certain that the concept "leaf" is formed by arbitrarily discarding these individual differences and by forgetting the distinguishing aspects.

We believe that we know something about the things themselves when we speak of trees, colors, snow, and flowers; and yet we possess nothing but metaphors for things, metaphors which correspond in no way to the original entities.

The various languages placed side by side show that with words it is never a question of truth, never a question of adequate expression; otherwise, there would not be so many languages. The "thing in itself" (which is precisely what the pure truth, apart from any of its consequences, would be) is likewise something quite incomprehensible to the creator of language and something not in the least worth striving for. This creator only designates the relations of things to men, and for expressing these relations he lays hold of the boldest metaphors.' To begin with, a nerve stimulus is transferred into an image: first metaphor. The image, in turn, is imitated in a sound: second metaphor. And each time there is a complete overleaping of one sphere, right into the middle of an entirely new and different one.

Are designations congruent with things? Is language the adequate expression of all realities? It is only by means of forgetfulness that man can ever reach the point of fancying himself to possess a "truth" of the grade just indicated. If he will not be satisfied with truth in the form of tautology, that is to say, if he will not be content with empty husks, then he will always exchange truths for illusions.

The liar is a person who uses the valid designations, the words, in order to make something which is unreal appear to be real. He says, for example, "I am rich," when the proper designation for his condition would be "poor." He misuses fixed conventions by means of arbitrary substitutions or even reversals of names. If he does this in a selfish and moreover harmful manner, society will cease to trust him and will thereby exclude him. What men avoid by excluding the liar is not so much being defrauded as it is being harmed by means of fraud. Thus, even at this stage, what they hate is basically not deception itself, but rather the unpleasant, hated consequences of certain sorts of deception. It is in a similarly restricted sense that man now wants nothing but truth: he desires the pleasant, life-preserving consequences of truth. He is indifferent toward pure knowledge which has no consequences; toward those truths which are possibly harmful and destructive he is even hostilely inclined.

...and woe betide fateful curiosity should it ever succeed in peering through a crack in the chamber of consciousness, out and down into the depths, and thus gain an intimation of the fact that humanity, in the indifference of its ignorance, rests on the pitiless, the greedy, the insatiable, the murderous clinging in dreams, as it were, to the back of a tiger.

What does man actually know about himself? Is he, indeed, ever able to perceive himself completely, as if laid out in a lighted display case? Does nature not conceal most things from him even concerning his own body in order to confine and lock him within a proud, deceptive consciousness, aloof from the coils of the bowels, the rapid flow of the blood stream, and the intricate quivering of the fibers! She threw away the key.