_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. For clarity we might indicate the mind and its functions in the following diagram: