Mach's _Science of Mechanics_ and Pearson's _Grammar of Science_. The
claims of 'induction' to be a method of establishing truths may be
fairly said to have been completely exposed. It is clearer now than it
was when Kant made the observation that each of the 'sciences' contains
just so much science as it contains mathematics, and that the Critical
Philosophy was fully justified in insisting that all science implies
universal _à priori_ postulates, though it went wrong in thinking that
these postulates are laws of the working of the human mind or are 'put
into' things by the human mind. How far Science has moved away from
crude sensationalistic empiricism may be estimated by a comparison of
the successive editions of the _Grammar of Science_. It must always have
been apparent to an attentive reader that the chapters of that
fascinating book which deal directly with the leading principles of
Physics and Biology are of very different quality from the earlier
chapters which expound, with many self-contradictions and much wrath
against metaphysicians and theologians whom the writer seems never to
have tried to understand, the fantastic 'metaphysics of the
telephone-exchange'. But the difference of quality is more marked in the
second edition than in the first, and in the (alas!) unfinished third
edition than in the second. So far, then, as the problem of the
unification of the sciences is concerned, the old prejudices which
divided the rationalist philosopher from the sensationalist scientific
man seem to have been, in the main, dissipated. We can see now that what
used to be called Philosophy and what used to be called Science are both
parts of one task, that they have a common method and presuppose a
common body of principles.

So far it may be said with truth that Philosophy is becoming more
faithful than Kant was himself to the leading ideas of 'Criticism', and
again that it is reverting once more, as it reverted in the days of