The Descent of Man

KNOWLEDGE was the cause of a temporary
but long-enduring moral deterioration as indicated
by the many foul customs, especially as
to marriage, of savage tribes. What does the
Jewish tradition of the moral degeneration of
man through his snatching at a knowledge forbidden
him by his highest instinct assert beyond
this?") as to lead them regularly to destroy
their own offspring, or to be quite devoid
of jealousy. There would have been no prudential
restraint from marriage, and the sexes
would have freely united at an early age. Hence
the progenitors of man would have tended to
increase rapidly; but checks of some kind, either
periodical or constant, must have kept
down their numbers, even more severely than
with existing savages. What the precise nature
of these checks were, we cannot say, any more
than with most other animals. We know that
horses and cattle, which are not extremely prolific
animals, when first turned loose in South
America, increased at an enormous rate. The