The Principles of Psychology, Volumes 1 and 2 are the 1890 set of books by William James that are lovingly combined into one complete book here. William James was 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 humans while the functions of the cerebrum itself become increasingly flexible and less localized as one moves along the same continuum.

James also discussed experiments on illusions (optical, auditory, etc.) and offered a physiological explanation for many of them, including that "the brain reacts by paths which previous experiences have worn, and makes us usually perceive the probable thing, i.e. the thing by which on previous occasions the reaction was most frequently aroused." Illusions are thus a special case of the phenomenon of habit.
In the use of the comparative method, James wrote, "instincts of animals are ransacked to throw light on our own...." By this light, James dismisses the platitude that "man differs from lower creatures by the almost total absence of instincts". There is no such absence, so the difference must be found elsewhere.

James believed that humans wielded far more impulses than other creatures. Impulses which, when observed out of their greater context, may have appeared just as automatic as the most basic of animal instincts. However, as man experienced the results of his impulses, and these experiences evoked memories and expectations, those very same impulses became gradually refined.

By this reasoning, William James arrived at the conclusion that in any animal with the capacity for memory, association, and expectation, behavior is ultimately expressed as a synthesis of instinct and experience, rather than just blind instinct alone.

Lovingly typeset for readability into two columns, all original figures inserted, both content pages have been moved to the beginning of the book, and both index pages have been organized at the end of the book.

William James was a philosopher who spoke out against the arrogant attitude of scientists who viewed religion as a biased relic of the past.
His writings frequently examined the relationship between science and religion. He also tried to defend society from the inhumane tendencies of science. His arguments against the cult of science and technitzism were quite effective and led to the new philosophical pragmatism movement.
Many consider The Varieties of Religious Experience as one of the seminal works in establishing a psychology of religion. This collection also includes The Principles of Psychology and Pragmatism.
Contents:
The Principles of Psychology
Psychology (Briefer Course)
The Will to Believe and Other Essays
Human Immortality
Talks to Teachers on Psychology and to Students on Some of Life's Ideals
The Varieties of Religious Experience
Pragmatism
A Pluralistic Universe
The Meaning of Truth
Some Problems of Philosophy
Memories and Studies
Essays in Radical Empiricism
Collected Essays and Reviews