Because the kernel of passionate love turns on the anticipation of the child to be born and its nature, it is quite possible for friendship, without any admixture of sexual love, to exist between two young, good-looking people of different sex, if there is perfect fitness of temperament and intellectual capacity.  In fact, a certain aversion for each other may exist also.  The reason of this is that a child begotten by them would physically or mentally have discordant qualities.  In short, the child’s existence and nature would not be in harmony with the purposes of the will to live as it presents itself in the species.

In an opposite case, where there is no fitness of disposition, character, and mental capacity, whereby aversion, nay, even enmity for each other exists, it is possible for love to spring up.  Love of this kind makes them blind to everything; and if it leads to marriage it is a very unhappy one.

And now let us more thoroughly investigate the matter.  Egoism is a quality so deeply rooted in every personality that it is on egotistical ends only that one may safely rely in order to rouse the individual to activity.

To be sure, the species has a prior, nearer, and greater claim on the individual than the transient individuality itself; and yet even when the individual makes some sort of conscious sacrifice for the perpetuation and future of the species, the importance of the matter will not be made sufficiently comprehensible to his intellect, which is mainly constituted to regard individual ends.

Therefore Nature attains her ends by implanting in the individual a certain illusion by which something which is in reality advantageous to the species alone seems to be advantageous to himself; consequently he serves the latter while he imagines he is serving himself.  In this process he is carried away by a mere chimera, which floats before him and vanishes again immediately, and as a motive takes the place of reality. This illusion is instinct.  In most instances instinct may be regarded as the sense of the species which presents to the will whatever is of service to the species.  But because the will has here become individual it must be deceived in such a manner for it to discern by the sense of the individual what the sense of the species has presented to it; in other words, imagine it is pursuing ends concerning the individual, when in reality it is pursuing merely general ends (using the word general in its strictest sense).

Outward manifestation of instinct can be best observed in animals, where the part it plays is most significant; but it is in ourselves alone that we can get to know its internal process, as of everything internal.  It is true, it is thought that man has scarcely any instinct at all, or at any rate has only sufficient instinct when he is born to seek and take his mother’s breast.  But as a matter of fact man has a very decided, clear, and yet complicated instinct—­namely,