Thinking is mind. Feeling is mind. Willing is mind. But for the sake of clearness we speak of feeling, thinking, and willing as being functions of mind. Mind acts by using these powers. But to what end does it act? What purpose does it serve? For these functions are not the reasons of being for the mind, even as motion—while the immediate purpose of the locomotive—is not its chief end. The steam engine may stand in the same spot while its wheels revolve madly; it may move along the tracks alone, and accomplish nothing; or it may transport a great train of loaded cars. Unless it moves to some definite point and carries merchandise or people there, it is a useless, indeed, a dangerous invention. We find, in fact, that it functions to the very definite end of taking man and his chattels to specified places.
And so it is with the mind. If it is thinking and feeling and willing only for the sake of exercising these mental powers, it might better not be. But what end do we actually find these functions serving?
Mind, with its powers of thinking, feeling, and willing, gives an external world of matter; an internal world of thought, and so relates them to each other as to make them serve man’s purposes. Thus these functions exist for accomplishment.
In the solving of a problem, for instance, the mind thinks, primarily; in the enjoyment of music it feels, primarily, though its feeling may be determined by the intellectual verdict on the music; in forcing its owner to sit at the piano and practice in the face of strong desire to attend the theater, it wills, primarily. Now one of its functions predominates; now another. But the whole mind, not a feeling section, or a thinking section, or a willing section, operates together to produce action. When I play the piano it calls on all my mind. I think the music. I feel it. I make my fingers play it. But the thinking, the feeling, and the willing act together to result in the fingers playing.
The mind, then, is an instrument of achievement. It fulfils its purpose when it makes matter serve useful ends.
Emotion or feeling is the function of the mind which associates a sense of pleasure or pain with every thought or act.
Feeling is the affective state of mind. By this we mean that it has the power to move us. And this emotion primarily does; for our feeling of pleasure or pain moves us to action, as well as precedes and accompanies and follows action. The word emotion is usually employed to denote an acute feeling state, while the word mood denotes a prolonged feeling condition, i. e., a less acute emotional state. The word feeling, however, is used to cover both; for in each case the sensational element manifests itself in a definite physical affect, pleasurable or painful in some degree.
Thinking is a conscious mental activity exercised to evolve ideas from perceptions, and to combine and compare these ideas to form judgments.
Intellection, or thinking, might be explained as the mental process which converts sensation into percepts, groups percepts to form concepts or ideas, stores away ideas and sensations for future use, and recalls them when needed—the recalling being memory—and by reason combines, compares, and associates ideas to form judgments, then compares judgments to form new judgments. The process of intellect we name by terms denoting activity, such as intellection, thinking, the stream of thought, and the latter describes it most truly.
Volition or will is the function of the mind which compels the expression of thought or feeling in action.