[1] James is considered to be a leading thinker of the late 19th century, one of the most influential philosophers of the United States, and the "Father of American psychology.

[6] A survey published in American Psychologist in 1991 ranked James's reputation in second place,[7] after Wilhelm Wundt, who is widely regarded as the founder of experimental psychology.

He was the son of Henry James Sr., a noted and independently wealthy Swedenborgian theologian well acquainted with the literary and intellectual elites of his day.

The intellectual brilliance of the James family milieu and the remarkable epistolary talents of several of its members have made them a subject of continuing interest to historians, biographers, and critics.

The family made two trips to Europe while William James was still a child, setting a pattern that resulted in thirteen more European journeys during his life.

James wished to pursue painting, his early artistic bent led to an apprenticeship in the studio of William Morris Hunt in Newport, Rhode Island, but his father urged him to become a physician instead.

[12] He was subject to a variety of psychological symptoms which were diagnosed at the time as neurasthenia, and which included periods of depression during which he contemplated suicide for months on end.

He took a break in the spring of 1865 to join naturalist Louis Agassiz on a scientific expedition up the Amazon River, but aborted his trip after eight months, as he suffered bouts of severe seasickness and mild smallpox.

[13] James's time in Germany proved intellectually fertile, helping him find that his true interests lay not in medicine but in philosophy and psychology.

[14] He interacted with a wide array of writers and scholars throughout his life, including his godfather Ralph Waldo Emerson, his godson William James Sidis, as well as Charles Sanders Peirce, Bertrand Russell, Josiah Royce, Ernst Mach, John Dewey, Macedonio Fernández, Walter Lippmann, Mark Twain, Horatio Alger, G. Stanley Hall, Henri Bergson, Carl Jung, Jane Addams and Sigmund Freud.

James's acquaintance with the work of figures like Hermann Helmholtz in Germany and Pierre Janet in France facilitated his introduction of courses in scientific psychology at Harvard University.

[15] During his Harvard years, James joined in philosophical discussions and debates with Charles Peirce, Oliver Wendell Holmes, and Chauncey Wright that evolved into a lively group informally known as The Metaphysical Club in 1872.

Du Bois, G. Stanley Hall, Ralph Barton Perry, Gertrude Stein, Horace Kallen, Morris Raphael Cohen, Walter Lippmann, Alain Locke, C. I. Lewis, and Mary Whiton Calkins.

[17] Following his January 1907 retirement from Harvard, James continued to write and lecture, publishing Pragmatism, A Pluralistic Universe, and The Meaning of Truth.

James sailed to Europe in the spring of 1910 to take experimental treatments for his heart ailment that proved unsuccessful, and returned home on August 18.

These works criticized both the English associationist school and the Hegelianism of his day as competing dogmatisms of little explanatory value, and sought to re-conceive the human mind as inherently purposive and selective.

[23][24][25][26] In simple terms, his philosophy and writings can be understood as an emphasis on "fruits over roots," a reflection of his pragmatist tendency to focus on the practical consequences of ideas rather than become mired in unproductive metaphysical arguments or fruitless attempts to ground truth in abstract ways.

Additional tenets of James's pragmatism include the view that the world is a mosaic of diverse experiences that can only be properly interpreted and understood through an application of "radical empiricism".

[33] Both James and his colleague, Charles Sanders Peirce, coined the term "cash value":[34] When he said that the whole meaning of a (clear) conception consists in the entire set of its practical consequences, he had in mind that a meaningful conception must have some sort of experiential "cash value," must somehow be capable of being related to some sort of collection of possible empirical observations under specifiable conditions.A statement's truthfulness is verifiable through its correspondence to reality, and its observable effects of putting the idea to practice.

In this sense the pragmatic theory of truth applied Darwinian ideas in philosophy; it made survival the test of intellectual as well as biological fitness.

"[38] On the other hand, his friend, colleague, and another key founder in establishing pragmatist beliefs, Charles S. Peirce, dives deeper in defining these consequences.

Both argued that one must always adhere to fallibilism, recognizing of all human knowledge that "None of our beliefs are quite true; all have at least a penumbra of vagueness and error", and that the only means of progressing ever-closer to the truth is to never assume certainty, but always examine all sides and try to reach a conclusion objectively.

"[47] Overall, James uses this line of reasoning to prove that our will is indeed free: because of our morality codes, and the conceivable alternate universes where a decision has been regarded different from what we chose.

[46] In James's model of free will, choice is deterministic, determined by the person making it, and it "follows casually from one's character, values, and especially feelings and desires at the moment of decision.

Inspired by a report by Benjamin Paul Blood in 1874,[59][60] James experimented with inhaled nitrous oxide, upon which he experienced a "tremendously exciting sense of an intense metaphysical illumination" in which "every opposition ... vanished in a higher unity" and "the ego and its objects ... are one.

These criteria are as follows: For James, the first two attributes, ineffability and the noetic quality, "will entitle any state to be called mystical, in the sense in which I use the word."

"[64] He uses a number of historical examples to illustrate the presence of these attributes in geographically and temporally disparate instances, concluding that the mystical experience "is on the whole pantheistic and optimistic, or at least the opposite of pessimistic.

This obvious answer to a seemingly trivial question has been the central concern of a century-old debate about the nature of our emotions.It all began in 1884 when William James published an article titled "What Is an Emotion?

During this act of escape, the body goes through a physiological upheaval: blood pressure rises, heart rate increases, pupils dilate, palms sweat, muscles contract in certain ways (evolutionary, innate defense mechanisms).

He was highly skeptical of applying Darwin's formula of natural selection to human societies in a way that put the Anglo-Saxons on top of the chain.