adultery or rape, all merely in order to serve the species in the most efficient way, although at the cost of the individual, in accordance with the will of nature which is everywhere sovereign. Instinct, in fact, is always an act which seems to be in accordance with the conception of an end, and yet is entirely without such a conception. Nature implants it wherever the acting individual is incapable of understanding the end, or would be unwilling to pursue it. Therefore, as a rule, it is given only to the brutes, and indeed especially to the lowest of them which have least understanding; but almost only in the case we are here considering it is also given to man, who certainly could understand the end, but would not pursue it with the necessary ardour, that is, even at the expense of his individual welfare. Thus here, as in the case of all instinct, the truth assumes the form of an illusion, in order to act upon the will. It is a voluptuous illusion which leads the man to believe he will find a greater pleasure in the arms of a woman whose beauty appeals to him than in those of any other; or which indeed, exclusively directed to a single individual, firmly convinces him that the possession of her will ensure him excessive happiness. Therefore he imagines he is taking trouble and making sacrifices for his own pleasure, while he does so merely for the maintenance of the regular type of the species, or else a quite special individuality, which can only come from these parents, is to attain to existence. The character of instinct is here so perfectly present, thus an action which seems to be in accordance with the conception of an end, and yet is entirely without such a conception, that he who is drawn by that illusion often abhors the end which alone guides it, procreation, and would like to hinder it; thus it is in the case of almost all illicit love affairs. In accordance with the character of the matter which has been explained, every lover will experience a marvellous disillusion after the pleasure he has at last attained, and will wonder that what was so
