has gone most closely hand-in-hand with the mastery of fresh
masses of detail, pure mathematics, and again why the present state of
what is loosely called 'evolutionary' science is so unsatisfactory to
any one who has a high ideal of what a science ought to be. It exhibits
at once an enormous mass of detailed information and an apparently
hopeless vagueness about the meaning of the 'laws' by which all this
detail is to be co-ordinated, the reasons for thinking these laws true,
and the precise range of their significance. The work of men like
Cantor, Dedekind, Frege, Whitehead, Russell, is providing us with an
almost unexceptional theory of the first principles required for pure
mathematics. We are already in a position to say with almost complete
freedom from uncertainty what undefined simple notions and
undemonstrated postulates we have to employ in the science and to
express these ultimates without ambiguity. 'Evolutionary science,' rich
as is its information about the details of the processes going on in the
organic world, seems still to await its Frege or Russell. It talks, for
example, much of 'hereditary' and non-hereditary peculiarities, and some
of us can remember a time when our friends among the biologists seemed
almost ready to put each other to the sword for differences of opinion
about the inheritability of certain characteristics; but no one seems to
trouble himself much with the question a philosopher would think most
important of all--precisely what is meant by the metaphor of
'inheritance' when it is applied to the facts of biology. (Indeed, it is
still quite fashionable to talk not merely as if a 'character' were,
like a house or an orchard, a _thing_ which can be transferred bodily
from the possession of a parent to the possession of the offspring, but
even as though an 'heir' could 'inherit' himself.)

This last remark leads me to a further consideration. Science and
Philosophy are alike created by the simple determination to be
_thorough_ in our thinking about the problems which all things and
events present to us, to use no terms whose meaning is ambiguous, to
assert no propositions as true until we are satisfied that they are
either directly apprehended as true, or strictly deducible from other
propositions which are thus apprehended. But now that the area of facts
open to our exploration has become far too vast for a modern Francis
Bacon to 'take all knowledge for his province', and convenience h