when the equation has been brought to its lowest
terms, the symbols remain symbols still. Hence the reasonings contained
in "First Principles" afford no support to either of the antagonist
hypotheses respecting the ultimate nature of things. Their implications
are no more materialistic than they are spiritualistic, and no more
spiritualistic than they are materialistic. The establishment of
correlation and equivalence between the forces of the outer and the
inner worlds serves to assimilate either to the other, according as we
set out with one or the other. He who rightly interprets the doctrine
propounded in "First Principles" will see that neither the forces of
the outer, nor the forces of the inner, world can be taken as ultimate.
He will see that, though the relation of subject and object renders
necessary to us the antithetical conceptions of Spirit and Matter, the
one is no less than the other to be regarded as but a sign of the
Unknown Reality which underlies both.

In logical order the formulation of "First Principles" should have been
followed by the application of them to Inorganic Nature. This great
division of Mr. Spencer's subject is passed over, however; partly
because, even without it, the scheme is too extensive to be carried out
in the lifetime of one man; and partly because the interpretation of
Organic Nature, after the proposed method, is of more immediate
importance. Before noting how Mr. Spencer applies his fundamental
principles to the interpretation of the phenomena of life, it may be
well to put before the reader's eye the "formula of evolution" in the
author's own language: "Evolution is an integration of matter and
concomitant dissipation of motion; during which the matter passes from
an indefinite, incoherent homogeneity to a definite, coherent
heterogeneity; and during which the retained motion undergoes a parallel
transformation." This law of evolution is equally applicable to all
orders of phenomena,--"astronomic, geologic, biologic, psychologic,
sociologic, etc.,"--since these are all component parts of one cosmos,
though disguised from one another by conventional groupings. It is
obvious that, so long as evolution is merely established by induction,
it belongs, not to philosophy, but to science. To belong to philosophy
it must be deduced from the persistence of force. Mr. Spencer holds that
this can be done. For any finite aggregate, being unequally exposed to
surrounding forces, will b