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.
CHAPTER VIII.
CLASSIFICATION AND DESCRIPTION OF THE MENTAL POWERS.
We now proceed to the classification and description of the mental powers.