The reason of this curious fact is given in this sentence:
“Love-marriages are formed in the interest of the species, not of the
individuals. True, the parties concerned imagine that they are providing
for their own happiness; but their real [unconscious] aim is something
foreign to their own selves—namely, the procreation of an individual
whose existence becomes possible only through their marriage.”
What urges a man on to this sacrifice of individual happiness to the
welfare of his offspring is, as already intimated, a blind instinct
known as Love. The universal _Will_ (Schopenhauer’s fetish, or name for
an impersonal deity underlying all phenomena) has implanted this blind
instinct in man, for the same reason that it implants so many other
instincts in various animals—to induce the parents to undergo any amount
of labour, and even danger to life, for the sake of benefiting the
offspring, and thus preserving the species. All these animals, like the
lovers, are urged on blindly to sacrifice themselves in the belief that
they are doing it for their own pleasure and benefit; whereas it is all
in the interest of their offspring.
Why was the _Will_ compelled to implant this blind instinct in man?
Because man is so selfish wherever guided by reason, that it would have
been unwise to entrust so important a matter as the welfare of coming
generations to his intellect and prudence. Prudence would tell young
people to choose not the most attractive and healthy partners, who would
be able to transmit their excellence to the next generation, but the
ones who are most liberally supplied with money and useful friends. That
is, they would invariably look out first for “Number One,” indifferent
to the deluge that might come after them. It was to neutralise this
selfishness that the _Will_ created the instinct of Love, which impels a
man to marry not the woman who will make _him_ the most happy and
comfortable, but whose qualities, combined with his own, will be likely
to produce a harmonious, well-made group of children.
Schopenhauer’s _Will_, it must be understood, is an æsthetic sort of a
chap. He has his hobbies, and one of these hobbies is the desire to
preserve the species in its typical purity and beauty. There are a
thousand accidents of climate, vice, disease, etc., that tend to vitiate
the type of each species; but Love strives for ever to restore a
harmonious balance, by producing a mutual infatuation in two beings
whose combined (and opposite) defects will neutralise one another in the
offspring.