Thus, it is maintained that there is a real external world presented in
our experience--not a world which we have a right to regard as the
sensations or ideas of any mind. It is maintained that we have
evidence that there are minds in certain relations to that world, and
that we can, within certain limits, determine these relations. It is
pointed out that the plain man's belief in the activity of his mind and
his notion of the significance of purposes and ends are not without
justification. It is indicated that theism is a reasonable doctrine,
and it is held that the human will is free in the only proper sense of
the word "freedom." Throughout it is taken for granted that the
philosopher has no private system of weights and measures, but must
reason as other men reason, and must prove his conclusions in the same
sober way.

I have written in hopes that the book may be of use to undergraduate
students. They are often repelled by philosophy, and I cannot but
think that this is in part due to the dry and abstract form in which
philosophers have too often seen fit to express their thoughts. The
same thoughts can be set forth in plain language, and their
significance illustrated by a constant reference to experiences which
we all have--experiences which must serve as the foundation to every
theory of the mind and the world worthy of serious consideration.

But there are many persons who cannot attend formal courses of
instruction, and who, nevertheless, are interested in philosophy.
These, also, I have had in mind; and I have tried to be so clear that
they could read the work with profit in the absence of a teacher.

Lastly, I invite the more learned, if they have found my "System of
Metaphysics" difficult to understand in any part, to follow the simple