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.