Only a living entity can have goals or can originate them. And it is only a
living organism that has the capacity for self-generated, goal-directed action.
On the physical level, the functions of all living organisms, from the
simplest to the most complex—from the nutritive function in the single cell of
an amoeba to the blood circulation in the body of a man—are actions generated
by the organism itself and directed to a single goal: the maintenance of the
organism’s life.
When applied to physical phenomena, such as the automatic functions of an
organism, the term “goal-directed” is not to be taken to mean “purposive” (a
concept applicable only to the actions of a consciousness) and is not to imply
the existence of any teleological principle operating in insentient nature. I
use the term “goal-directed,” in this context, to designate the fact that the
automatic functions of living organisms are actions whose nature is such that
they result in the preservation of an organism’s life.