William James

The Principles of Psychology, Volume 1 William James

The Principles of Psychology is an 1890 book about psychology by William James, an American philosopher and psychologist who trained to be a physician before going into psychology. There are four methods from James' book: stream of consciousness (James' most famous psychological metaphor); emotion (later known as the James-Lange theory); habit (human habits are constantly formed to achieve certain results); and will (through James' personal experiences in life). The openings of The Principles of Psychology presented what was known at the time of writing about the localization of functions in the brain: how each sense seemed to have a neural center to which it reported and how varied bodily motions have their sources in other centers. The particular hypotheses and observations on which James relied are now very dated, but the broadest conclusion to which his material leads is still valid, which was that the functions of the "lower centers" (beneath the cerebrum) become increasingly specialized as one moves from reptiles, through ever more intelligent mammals, to inhumans while the functions of the cerebrum itself become increasingly flexible and less localized as one moves along the same continuum.