l
perspective, are imaginary. No such special and exclusive manifolds can
be defined as having been then and there realized. But we have a
geological knowledge of this period, that fulfils the formal demands of
natural science, in so far as we can construct this and countless other
specific experiences with reference to it.

[Sidenote: The General Development of Science.]

Sect. 49. Science, then, is to be understood as springing from the
practical necessity of anticipating the environment. This anticipation
appears first as congenital or acquired reactions on the part of the
organism. Such reactions imply a fixed coordination or system in the
environment whereby a given circumstance determines other circumstances;
and science proper arises as the formulation of such systems. The
requirement that they shall apply to the phenomena that _confront_ the
will, determines their spacial, temporal, and quantitative form. The
progress of science is marked by the growth of these conceptions in the
direction of comprehensiveness on the one hand, and of refinement and
delicacy on the other. Man lives in an environment that is growing at
the same time richer and more extended, but with a compensatory
simplification in the ever closer systematization of scientific
conceptions under the form of the order of nature.

[Sidenote: The Determination of the Limits of Natural Science.]

Sect. 50. At the opening of this chapter it was maintained that it is a
function of philosophy to criticise science through its generating
problem, or its self-imposed task viewed as determining its province and
selecting its categories. The above account of the origin and method of
science must suffice as a definition of its generating problem, and
afford the basis of our answer to the question of its limits. Enough has
been said to make it clear that philosophy is not in the field of
science, and is therefore not entitled to contest its result in detail
or even to take sides within the province of its special problems.
Furthermore, philosophy should not aim to restrain science by the
imposition of external barriers. Whatever may be said of the sufficiency
of its categories in any region of the world, that body of truth of
which mathematics, mechanics, and physics are the foundations, must be
regarded as a whole that tends to be all-comprehensive in its own terms.
There remains for philosophy, then, the critical examination of these
terms, and the apprai