Why therefore should we recognize two kinds of desires, instead of
acknowledging only one kind in the living body? Because nature differs
from the body to which it gives life. Nature is anterior to the body
because it is nature that organizes the body by moulding it, and
shaping it; consequently, the origin of desire is not in nature, but
in the passions of the living body. If the latter suffer, it aspires
to possess things contrary to those that make it suffer, to make
pleasure succeed pain, and satisfaction succeed need. Nature, like a
mother, guesses the desires of the body that has suffered, tries to
direct it, and to lure it back. While thus trying to satisfy it, she
thereby shares in its desires, and she proposes to accomplish the same
ends. It might be said that the body, by itself, possesses desires and
inclinations; that nature has some only as a result of the body, and
because of it; that, finally the soul is an independent power which
grants or refuses what is desired by the organism.