individuals of value to society.

So let us not go erring about in the philosophical ether, imagining that
because the _amoeba_ may not be specialized for anything over and above
nutrition and reproduction that these are necessarily the "main
business" or "chief ends" of human societies. Better say that although
we have become developed and specialized for a million other activities
we are still bound by those fundamental necessities. As to "Nature's
purposes" about which the older sex literature has had so much to say,
the idea is essentially religious rather than scientific. If such
"purposes" indeed exist in the universe, man evidently does not feel
particularly bound by them. We do not hesitate to put a cornfield where
"Nature" had a forest, or to replace a barren hillside by the sea with a
city.

Necessities and possibilities, not "purposes" in nature, claim our
attention--reproduction being one of those embarrassing necessities,
viewed through the eyes of man, the one evaluating animal in the world.
Thus in reasoning from biology to social problems, it is fundamental to
remember that man as an animal is tremendously differentiated in
functions, and that most of the activities we look upon as distinctively
human depend upon the body rather than the germ-cells.

It follows that biology is the foundation rather than the house, if we
may use so crude a figure. The solidity of the foundation is very
important, but it does not dictate the details as to how the
superstructure shall be arranged.

Civilization would not be civilization if we had to spend most of our
time thinking about the biological basis. If we wish to think of