Robert S.Woodworth

It would be hard to mention any activity that is mental without being physical at the same time.

the brain is just as truly a bodily organ as the heart or stomach.

psychology examines what are called "mental" activities, and that it studies them as the performances of the whole individual rather than as executed by the several organs.

psychology is the study of conscious activities?

When a person performs any act, there are, or may be, two sorts of facts to be observed, the "objective" and the "subjective".

The objective facts consist of movements of the person's body or of any part of it, secretions of his glands (as flow of saliva or sweat), and external results produced by these bodily actions--results such as objects moved, path and distance traversed, hits on a target, marks made on paper, columns of figures added, vocal or other sounds produced, etc., etc. Such objective facts can be observed by another person.

The subjective facts can be observed only by the person performing the act. While another person can observe, better indeed than he can himself, the motion of his legs in walking, he alone can observe the sensations in the joints and muscles produced by the leg movement.

That one of all the sciences that has the closest contacts with psychology is human and animal physiology. Broadly defined, physiology is that part of biology that studies functions or activities; and, so defined, it includes psychology as part of itself. In practice, psychology devotes itself to desire, thought, memory, and such "mental functions", while physiology concentrates its effort upon "bodily functions" like digestion and circulation.

Physiology has studied the action of the vocal organs and the location of the brain centers concerned in speech, while

psychology has studied the child's process of learning to speak and the relation of speech to thought, and is more apt to be interested in stuttering, slips of the tongue, and other speech disturbances which are said to be "mental rather than physical".