' of
everything, on the other,--neither philosopher owning any strict and
systematic disciples to-day, each being to posterity a warning as well
as a stimulus,--show us that the only possible philosophy must be a
compromise between an abstract monotony and a concrete heterogeneity.
But the only way to mediate between diversity and unity is to class the
diverse items as cases of a common essence which you discover in them.
Classification of things into extensive 'kinds' is thus the first step;
and classification of their relations and conduct into extensive 'laws'
is the last step, in their philosophic unification. A completed
theoretic philosophy can thus never be anything more than a completed
classification of the world's ingredients; and its results must always
be abstract, since the basis of every classification is the abstract
essence embedded in the living fact,--the rest of the living fact being
for the time ignored by the classifier. This means that none of our
explanations are complete. They subsume things under heads wider or
more familiar; but the last heads, whether of things or of their
connections, are mere abstract genera, data which we just find in
things and write down.

When, for example, we think that we have rationally explained the
connection of the facts _A_ and _B_ by classing both under their common
attribute _x_, it is obvious that we have really explained only so much
of these items as _is x_. To explain the connection of choke-damp and
suffocation by the lack of oxygen is {68} to leave untouched all the
other peculiarities both of choke-damp and of suffocation,--such as
convulsions and agony on the one hand, density and explosibility on the
other. In a word, so far as _A_ and _B_ contain _l_, _m_, _n_, and
_o_, _p_, _q,_ respectively, in addition to _x_, they are not explained
by _x_. Each additional particularity makes its distinct appeal. A
single explanation of a fact only explains it from a single point of
view. The entire fact is not accounted for until each and all of its
characters have been classed with their likes elsewhere. To apply this
now to the case of the universe, we see that the explanation of the
world by molecular movements explains it only so far as it actually
_is_ such movements. To invoke the 'Unknowable' explains only so much
as is unknowable, 'Thought' only so much as is thought, 'God' only so
much as is God. _Which_ thought? _Which_ God?--are questions tha