THE ORGANISM AS A PSYCHOPHYSICAL SYSTEM         91
According to Whitehead, therefore, there was a date in the
history of the world on which consciousness first appeared. More-
over, his view seems to allow only a minor function to conscious-
ness. It enables something to be done better than it could have
been done without it. No doubt the choice between this and the
alternative, that consciousness has always been present, is a
matter of prejudice or taste, incapable of convincing argument
either way. To many, the more satisfying hypothesis is that all
process (in Whitehead's sense) is of the nature of experience, and
—contrary to Whitehead—that all experience is in its degree
conscious. If this is so, we must ascribe consciousness to every
living agent, such as a plant cell or a bacterium, and even (if the
continuity of nature is not to be broken) to an electron. Since,
however, we are primarily concerned with living organisms, we
need not extend our discussion beyond them.
One of the reasons for a certain reluctance to attribute
consciousness to a tissue cell or to a bacterium is that many things
which we do, apparently without being conscious of doing them,
are so much more complicated than anything which these lowly
organisms can do that it seems unnecessary to suppose that their
simple responses involve consciousness. The problem of the
apparently unconscious reflexes of the higher organisms has
already been touched on in chapter i, where it was pointed out
that, on the view that a higher organism is a nexus of agents, a
reflex action does not, or need not, involve the Central Agent at
all. Any consciousness accompanying the action would therefore
not be consciousness on the part of the Central Agent, but of
agents of a lower order. Moreover, there are many actions which
may be reflex on most occasions but consciously controlled on
others; for instance, walking, or the fixation of the eyes on the
object we are looking at. It may be that these actions are normally
controlled by subordinate centres of integration (subjects of a
lower order than the Central Agent) whose activities do not
normally form discriminable constituents of the objective datum
for an occasion of the Central Agent, though under special
circumstances they may do so. Possibly some of the operations
of the 'unconscious mind' are to be explained in the same way,
especially those which must involve trains of thinking of which
we know nothing until their final product is prehended by the
Central Agent as the solution of a forgotten problem. It may be
that the operative subject here is one of the higher sub-agents in