We are now to commence an examination of the various powers and
operations of the human mind, for the purpose of illustrating the grand
aim of the Author in the creation of all things.

In pursuing this course, it is needful, first, to refer to the apparent
diversities in systems of mental philosophy, for the purpose of
justifying the classification and the terms to be employed hereafter.

There is nothing more hackneyed than the complaints against metaphysics
as abstruse, difficult of comprehension, and unpractical, while the
various writers on this science seem more or less divided into opposing
schools. Notwithstanding this, there are reasons for maintaining a real
agreement in all systems of mental philosophy, at least in essentials,
and the following considerations lead to such a conclusion:

In the first place, the nature of the subject investigated would
necessarily tend to such a result; for that subject is the human mind,
not in its specific peculiarities, but in those generic phenomena which
are common to all minds; just as the natural philosopher investigates
those properties of matter which are common to a class, and not the
specific peculiarities that distinguish individual masses or particles.
Now, as those who direct their investigations to mental phenomena are
all drawing a picture from the same pattern, it is properly inferred
that in the main outlines there must be a general resemblance.

Another reason for this conclusion is the mode of investigation pursued.
It is simply observing, first, the phenomena of our own minds, and then
comparing them with those of other minds as exhibited in looks, words,
and actions, and thus educing generic resemblances and specific
differences. It is the generic resemblances only that constitute the
faculties and laws of mind which are to be described, classified, and

Another reason for inferring such an agreement of systems is the fact,
not only that all human minds have common phenomena, but that they have
provided themselves with terms to express them, so that they succeed in
so far understanding each other as to make comparisons of their mental

The same agreement may be inferred, also, when we consider that mental
philosophy treats, not of new ideas, or new combinations of ideas, but
of knowledge which is already in the mind. The process to be pursued,
then, involves a reference to what we have ourselves experienced; it is
an examination of our own feelings, thoughts, and volitions. These are
subjects of which we are competent judges, and in regard to which we can
be certain as to what is correct or incorrect, more than we can be in
reference to any other kind of knowledge.

From these considerations, it is inferred that all systems of mental
philosophy will resemble each other just so far as they are true, and
that the difference must be mainly in modes of presenting the subject.
Inasmuch as writers on mental science are drawing a picture of those
experiences of their own minds which are common to the whole race, they
must in the main resemble each other, though some may be more imperfect,
vague, and disconnected than others.

It may be useful to indicate the causes which have combined to produce
perplexity and apparent diversities among writers on mental science.

The first cause is the want of an accurate medium of communication by
which one mind can compare its experience with the experience of other
minds. In natural science, when the philosopher instructs in reference
to the properties of matter, all the terms employed can be made definite
by appeals to the senses. For example, if it is not understood what is
meant by a _pungent_ smell, such a smell can be produced, and then there
is a perfectly clear idea of what is meant by the term. But in mental
science, when the term _reason_ or the term _understanding_ is employed,
no such perfect and definite mode is at command to illustrate the

On the contrary, in this science, a single term is often used with
various meanings, each use, however, including some common idea, while
the extent or limitation in every case is to be determined by the
connection. For example, the term _heart_ is used sometimes to signify
the chief organ of physical life, sometimes it signifies the mind
itself. In a more limited use it denotes the feelings, and in a still
more restricted sense it expresses the leading interest of the mind.
This involves a constant process of reasoning to decide the meaning of
the term.

Another perplexity in mental science has arisen from an unwarrantable
use of terms by writers. In some instances new distinctions in mental
analysis have been originated, and then terms have been used to express
these distinctions which never before were employed in this limited
sense. Of course, in reading their works, the mind is confused by
meeting terms that in common use recall one signification, when the
writer employs them in another.

In other cases, such writers have formed new classifications of mental
phenomena, and employed new terms to express them, and thus an
impression is made that something new has been discovered, or a new
system evolved. For example, Brown arranges the intellectual operations
of mind in but two general classes, and calls them _simple suggestion_
and _relative suggestion_. But his work, in this respect, presents only
a new classification and new terms, but no new ideas.

Another difficulty in mental science has arisen from the fact that many
writers on this subject have failed in accurate analysis of the
phenomena of mind, and, of course, have not succeeded in conveying clear
and distinct ideas to their readers. For example, some metaphysicians
have never discriminated between _desire_ and _choice_, but have written
as if they were the same thing. Thus they have affirmed things which
were true in reference to one of these mental acts, and false in regard
to the other. This has produced mistiness of apprehension or false
conceptions in their readers. Some understand the writer one way and
dispute his positions, others understand him another way and defend
them, because what he says is true of one act and false of the other,
while both acts are spoken of as one and the same.

Meantime the great mass of readers have never been accustomed to any
accurate analysis, or even to any fixed observation of their own mental
states. They are, therefore, unprepared to detect these defects in the
writers on mental science, and are easily confused and perplexed.

Another difficulty has arisen from false ideas as to the origin and
proper use of words. In most minds an impression has been generated that
there is an inherent meaning belonging to the words of a language. They
do not consider that in the formation of language the ideas come first,
and that the words are only conventional signs which men agree in using
to express these ideas. Writers often speak of words which by long usage
have been connected with certain ideas, as if they ought not to be so
employed. They do not consider that the fact that men have used a word
for a given idea, and understand each other, is the very thing which
establishes its proper use and meaning.

If, then, in all time and in all nations, mankind have classified and
given names to their mental states, the classification and the names are
true and proper, and no philosopher should claim that these are
incorrect. The object of language is to enable men to communicate their
ideas, and that language is best which enables them to do it the most
extensively and the most accurately.

It is maintained, then, that there is a _system_ of mental philosophy
which is understood by all mankind; that there are words in common use
by which it can be clearly and definitely described and expressed,
either by single terms or by circumlocution; that it is recognized in
the Bible; and that, substantially, it is the system taught by all
writers on mental science, some teaching one portion and some another.
It is maintained, also, that no such writer has taught any thing of any
importance _that is true_ which can not be translated into the language
of common life, so as to be readily comprehended even by persons of
ordinary capacity and education.

There is no difficulty in leading any mind of ordinary capacity to
notice the several classes of mental operations introduced in this work,
and in all nations and languages these facts are recognized and terms
are provided to express them.

Some persons object to speaking of any mental phenomena as _states_ of
mind, because it is claimed that the mind is _active_ in all. Thus
sensations are claimed to be acts of mind instead of passive states
caused by material objects. In regard to this and various other
objections urged against this mode of classification and nomenclature,
it may be remarked that the thing aimed at is simply, by means of a
description, to point out what is meant. When this is understood, it
does not change our idea to give it a name. We know by our own
experience what it is to have a sensation, and calling it a _state_ or
an _act_ does not alter our idea of the fact.

In using words, all we have to do is to _convey our meaning_, either by
description or illustration, and when we have done this, to select a
word to express it; and that word is best for this purpose which would
recall this meaning to the greatest number of persons who have
previously used it in this sense.

For this reason, it is most proper to use terms employed in common life
to express the phenomena treated of in mental science, instead of
instituting new terms, which, to most persons, have never had the
intended ideas connected with them.

This method is adopted in the following pages; but it is important to
remember that, while these words are used both in common life and by
metaphysical writers with the meaning here indicated, they are often
used with other significations. Thus the word _to perceive_ is used not
only to signify the act of gaining ideas by the senses, but any act of
mind in noticing truths of any kind, either mental or external. So _to
conceive_ and _to perceive_ are often used interchangeably as meaning
the same thing.

But this does not render it necessary to seek any new terms to express
these ideas. All that is needful is to indicate that in classing and
describing mental phenomena we restrict ourselves to one exact and
uniform use of these terms, and this use is indicated in the description
or definition given.