ption of it will be a
corollary of their metaphysics and epistemology. The remainder of the
field of the old philosophical psychology, the introspective and
experimental analysis of special states of mind, is already the
province of a natural science which is becoming more and more free from
the stand-point and method of philosophy.

[Sidenote: Transition from Classification by Problems to Classification
by Doctrines. Naturalism. Subjectivism. Absolute Idealism. Absolute
Realism.]

Sect. 101. Reminding ourselves anew that philosophical problems cannot
be treated in isolation from one another, we shall hereinafter seek to
become acquainted with general stand-points that give systematic unity
to the issues which have been enumerated. Such stand-points are not
clearly defined by those who occupy them, and they afford no clear-cut
classification of all historical philosophical philosophies. But
system-making in philosophy is commonly due to the moving in an
individual mind of some most significant idea; and certain of these
ideas have reappeared so frequently as to define more or less clearly
marked tendencies, or continuous strands, out of which the history of
thought is forever weaving itself. Such is clearly the case with
_naturalism_. From the beginning until now there have been men whose
philosophy is a summation of the natural sciences, whose entire thought
is based upon an acceptance of the methods and the fundamental
conceptions of these disciplines. This tendency stands in the history
of thought for the conviction that the visible and tangible world which
interacts with the body is veritable reality. This philosophy is
realistic and empirical to an extent entirely determined by its belief
concerning being. But while naturalism is only secondarily
epistemological, _subjectivism_ and _absolute idealism_ have their very
source in the self-examination and the self-criticism of thought.
Subjectivism signifies the conviction that the knower cannot escape
himself. If reality is to be kept within the range of possible
knowledge, it must be defined in terms of the processes or states of
selves. _Absolute idealism_ arises from a union of this epistemological
motive with a recognition of what are regarded as the logical
necessities to which reality must submit. Reality must be both knowledge
and rational knowledge; the object, in short, of an absolute mind, which
shall be at once all-containing and systematic. This rational