," VI.

CHAPTER IV, sections 15-18. See Chapters VI and VII, "What we mean by
the External World," and "Sensations and 'Things,'" in my "System of
Metaphysics." In that work the discussion of the distinction between
the objective order of experience and the subjective order is completed
in Chapter XXIII, "The Distinction between the World and the Mind."
This was done that the subjective order might be treated in the part of
the book which discusses the mind and its relation to matter.

As it is possible that the reader may be puzzled by differences of
expression which obtain in the two books, a word of explanation is not
out of place.

In the "Metaphysics," for example, it is said that sensations so
connect themselves together as to form what we call the system of
material things (p. 105). It is intimated in a footnote that this is a
provisional statement and the reader is referred to later chapters.
Now, in the present book (sections 16-17), it is taught that we may not
call material things groups of sensations.

The apparent contradiction is due to the fact that, in this volume, the
full meaning of the word "sensation" is exhibited at the outset, and
sensations, as phenomena of the subjective order, are distinguished
from the phenomena of the objective order which constitute the external
world. In the earlier work the word "sensation" was for a while used
loosely to cover all our experiences that do not belong to the class
called imaginary, and the distinction between the subjective and
objective in this realm was drawn later (Chapter XXIII).

I think the present arrangement is the better one, as it avoids from
the outset the suggestion that the real world is something
subjective--our sensations or ideas--and thus escapes the idealistic
flavor which almost inevitably attaches to the other treatment, until
the discussion is completed, at least.

CHAPTER V, sections 10-21. See Chapters VIII and IX, "System of
Metaphysics," "The Distinction between Appearance and Reality" and "The
Significance of the Distinction."

Section 22. See Chapter XXVI, "The World as Unperceived, and the
'Unknowable,'" where Spencer's doctrine is examined at length, and
references are given. I think it is very important that the student
should realize that the "Unknowable" is a perfectly useless assumption
in philosophy, and can serve no purpose whatever.

CHAPTER VI, sections 23-25. See Chapters X and XI, "System of
Metap