

But while writing it, he had been investigating a dynamic psychology of the subconscious, which found a major place in his Gifford Lectures, published as "The Varieties of Religious Experience" in 1902. In his "Principles of Psychology" (1890), he declared that psychology is the scientific study of states of consciousness as such and that he intended to presume from the outset that the thinker was the thought.

Throughout his career, William James defended personal consciousness.
