William James modeled the functionalist school of psychology on the science of chemistry.

Functionalism

A philosophical approach emphasizing the roles or functions of consciousness and mental processes in adapting to the environment.

William James

An influential American psychologist and philosopher, known for his contributions to pragmatic philosophy and psychology, including theories of self and emotion.

Chemistry

The branch of science concerned with the substances of which matter is composed, their properties, reactions, and the use of such reactions to form new substances.