Only by means of forgetfulness can man ever arrive at imagining that he possesses "truth" in that degree just indicated. If he does not mean to content himself with truth in the shape of tautology, that is, with empty husks, he will always obtain illusions instead of truth. What is a word? The expression of a nerve-stimulus in sounds. But to infer a cause outside us from the nerve-stimulus is already the result of a wrong and unjustifiable application of the proposition of causality. How should we dare, if truth with the genesis of language, if the point of view of certainty with the designations had alone been decisive; how indeed should we dare to say: the stone is hard; as if "hard" was known to us otherwise; and not merely as an entirely subjective stimulus! We divide things according to genders; we designate the tree as masculine,[2] the plant as feminine:[3] what arbitrary metaphors! How far flown beyond the canon of certainty! We speak of a "serpent";[4] the designation fits nothing but the sinuosity, and could therefore also appertain to the worm. What arbitrary demarcations! what one-sided preferences given sometimes to this, sometimes to that quality of a thing! The different languages placed side by side show that with words truth or adequate expression matters little: for otherwise there would not be so many languages. The "Thing-in-itself" (it is just this which would be the pure ineffective truth) is also quite incomprehensible to the creator of language and not worth making any great endeavour to obtain. He designates only the relations of things to men and for their expression he calls to his help the most daring metaphors. A nerve-stimulus, first transformed into a percept! First metaphor! The percept again copied into a sound! Second metaphor! And each time he leaps completely out of one sphere right into the midst of an entirely different one. One can imagine a man who is quite deaf and has never had a sensation of tone and of music; just as this man will possibly marvel at Chladni's sound figures in the sand, will discover their cause in the vibrations of the string, and will then proclaim that now he knows what man calls "tone"; even so does it happen to us all with language. When we talk about trees, colours, snow and flowers, we believe we know something about the things themselves, and yet we only possess metaphors of the things, and these metaphors do not in the least correspond to the original essentials. Just as the sound shows itself as a sand-figure, in the same way the enigmatical _x_ of the Thing-in-itself is seen first as nerve-stimulus, then as percept, and finally as sound. At any rate the genesis of language did not therefore proceed on logical lines, and the whole material in which and with which the man of truth, the investigator, the philosopher works and builds, originates, if not from Nephelococcygia, cloud-land, at any rate not from the essence of things.