[William James, in the 1890s] began that metamorphosis of German psychology which was to alter the Teutonic worm of sensory content into the American… - Edwin Boring

It is not likely that the history of psychology can be written in the next three centuries without mention of Freud's name and still claim to be a general history of psychology... Perhaps, had Freud been smothered in his cradle, the times would have produced a substitute, It is hard to say. The dynamics of history lack control experiments.

The historical approach to understanding of scientific fact is what differentiates the scholar in science from the mere experimenter.

The gift of professional maturity comes only to the psychologist who knows the history of his science.