Trained as a physician, William James was a professor at Harvard and one of the founders of modern psychology. He helped create pragmatism, which evaluates ideas by the practical effects they produce in life. He also wrote on religious experience and the will to believe, always in a clear and accessible style.
Core ideas
An idea is true to the extent that it works and makes a practical difference
Consciousness is a continuous stream, not a sum of isolated pieces
Facing vital choices without definitive proof, we have the right to believe
The tradition: Pragmatist
Pragmatism is an American current that measures ideas by their practical consequences, not by an abstract correspondence with reality. William James was its greatest popularizer.
