so from
the standpoint of pure physics, biology takes up the tale afresh, and
devises means of its own for describing the particular ways in which
things hang together in virtue of their being alive. And biology finds
that it cannot conveniently abstract away the reference to time. It
cannot treat living things as machines. What does it do, then? It takes
the form of history. It states that certain things have changed in
certain ways, and goes on to show, so far as it can, that the changes
are on the whole in a certain direction. In short, it formulates
tendencies, and these are its only laws. Some tendencies, of course,
appear to be more enduring than others, and thus may be thought to
approximate more closely to laws of the timeless kind. But _x_, the
unknown quantity, the something or other that is not physical, runs
through them all, however much or little they may seem to endure. For
science, at any rate, which departmentalizes the world, and studies
it bit by bit, there is no getting over the fact that living beings
in general, and human beings in particular, are subject to an evolution
which is simple matter of history.

And now what about philosophy? I am not going into philosophical
questions here. For that reason I am not going to describe biology
as natural history, or anthropology as the natural history of man.
Let philosophers discuss what "nature" is going to mean for them. In
science the word is question-begging; and the only sound rule in
science is to beg as few philosophical questions as you possibly can.
Everything in the world is natural, of course, in the sense that things
are somehow all akin--all of a piece. We are simply bound to take in
the parts as parts of a whole, and it is just this fact that makes
philosophy not only possible but inevitable. All the same, this fact
does not prevent the parts from having their own specific natures and
specific ways of behaving. The people who identify the natural with
the physical are putting all their money on one specific kind of nature
or behaviour that is to be found in the world. In the case of man they
are backing the wrong horse. The horse to back is the horse that goes.
As a going concern, however, anthropology, as part of evolutionary
biology, is a history of vital tendencies which are not natural in
the sense of merely physical.

What are the functions of philosophy as contrasted with science? Two.
Firstly, it must be critical. It must police the