Powers," which is avowedly grounded on Newton's ideas.

[2] Mr Herbert Spencer, who also distinguishes between abstract and
concrete sciences, employs the terms in a different sense from that
explained above. He calls a science abstract when its truths are merely
ideal; when, like the truths of geometry, they are not exactly true of
real things--or, like the so-called law of inertia (the persistence in
direction and velocity of a motion once impressed) are "involved" in
experience but never actually seen in it, being always more or less
completely frustrated. Chemistry and biology he includes, on the
contrary, among concrete sciences, because chemical combinations and
decompositions, and the physiological action of tissues, do actually
take place (as our senses testify) in the manner in which the scientific
propositions state them to take place. We will not discuss the logical
or philological propriety of either use of the terms abstract and
concrete, in which twofold point of view very few of the numerous
acceptations of these words are entirely defensible: but of the two
distinctions M. Comte's answers to by far the deepest and most vital
difference. Mr Spencer's is open to the radical objection, that it
classifies truths not according to their subject-matter or their mutual
relations, but according to an unimportant difference in the manner in
which we come to know them. Of what consequence is it that the law of
inertia (considered as an exact truth) is not generalized from our
direct perceptions, but inferred by combining with the movements which
we see, those which we should see if it were not for the disturbing
causes? In either case we are equally certain that it _is_ an exact
truth: for every dynamical law is perfectly fulfilled even when it seems
to be counteracted. There must, we should think, be many truths in
physiology (for example) which are only known by a similar indirect
process; and Mr Spencer would hardly detach these from the body of the