"From the standpoint of observation, then, we must regard it as a highly probable hypothesis that the beginnings of the mental life date from as far back as the beginnings of life at large."

“In Aristotle the mind, regarded as the principle of life, divides into nutrition, sensation, and faculty of thought, corresponding to the inner most important stages in the succession of vital phenomena.”

“We call that psychical process, which is operative in the clear perception of a narrow region of the content of consciousness, attention.”

“The results of ethnic psychology constitute... our chief source of information regarding the general psychology of the complex mental processes.”

“The whole task of psychology can therefore be summed up in these two problems : What are the elements of consciousness ? What combinations do these elements undergo and what laws govern these combinations ?”

“If we take an unprejudiced view of the processes of consciousness, free from all the so-called association rules and theories, we see at once that an idea is no more an even relatively constant thing than is a feeling or emotion or volitional process. There exist only changing and transient ideational processes ; there are no permanent ideas that return again and disappear again.”