Functionalism

Functionalism was a direct response to the structuralist psychology of the 19th century, and stands as a stark contrast. Functionalist psychology, which was based largely in America, arose as a compliment to the contemporary scientific and philosophical theory of the time and place. The most influential of which was Charles Darwin's Theory of Evolution by Natural Selection, which served as both a scientific and a philosophical theory, and has shaped a great portion of western thinking since.

Functionalism lends itself to a more rationalist philosophy than its predecessor structuralism, and its proponents such as William James, John Dewey, and James Angell insisted on the priority of logical thought over trial-and-error experimentation (which was viewed by many functionalists as a weakness of structuralism). Functionalist theory, as would be expected from a theory sprung from evolutionary theory, views the mental activity of conscious agents as assiduous adaption to one's cognitive environment. Which as part of a larger scale is part of an organisms overall adaptive qualities heightening its survival value. Functionalism does little in the way of providing scientifically testable hypotheses. Rather than asking the question of how the mental process works, functionalists are concerned with the question of why the mind or a particular process of it works in the way it does. And of course the inevitable answer, at least from a Darwinian perspective, is that any particular facet of the cognitive experience is more than likely adaptive in some respect or in some way related to an adaptive feature of the organism. Otherwise it would not have been passed on through generations, and/or will likely not be past on to future generations.

Becoming increasingly agitated by the lack of testability of functional theories, as well as other relatively contemporary theories such as Psychoanalysis, by the late 19th century many psychologists began a trend toward what is now known as behaviorism.