THE EVIL ONE.—“Only the solitary are evil!”—thus spake Diderot, and Rousseau at once felt deeply offended. Thus he proved that Diderot was right. Indeed, in society, or amid social life, every evil instinct is compelled to restrain itself, to assume so many masks, and to press itself so often into the Procrustean bed of virtue, that we are quite justified in speaking of the martyrdom of the evil man. In solitude, however, all this disappears. The evil man is still more evil in solitude—and consequently for him whose eye sees only a drama everywhere he is also more beautiful. 500. AGAINST THE GRAIN.—A thinker may for years at a time force himself to think against the grain: that is, not to pursue the thoughts that spring up within him, but, instead, those which he is compelled to follow by the exigencies of his office, an established division of time, or any arbitrary duty which he may find it necessary to fulfil. In the long run, however, he will fall ill; for this apparently moral self-command will destroy his nervous system as thoroughly and completely as regular debauchery. 501. MORTAL SOULS.—Where knowledge is concerned perhaps the most useful conquest that has ever been made is the abandonment of the belief in the immortality of the soul. Humanity is henceforth at liberty to wait: men need no longer be in a hurry to swallow badly-tested ideas as they had to do in former times. For in those times the salvation of this poor “immortal soul” depended upon the extent of the knowledge which could be acquired in the course of a short existence: decisions had to be reached from one day to another, and “knowledge” was a matter of dreadful importance! Now we have acquired good courage for errors, experiments, and the provisional acceptance of ideas—all this is not so very important!—and for this very reason individuals and whole races may now face tasks so vast in extent that in former years they would have looked like madness, and defiance of heaven and hell. Now we have the right to experiment upon ourselves! Yes, men have the right to do so! the greatest sacrifices have not yet been offered up to knowledge—nay, in earlier periods it would have been sacrilege, and a sacrifice of our eternal salvation, even to surmise such ideas as now precede our actions. 502.