“There is a physical neurobiological substrate to all human knowledge, including thoughts, memories, perceptions and emotions. To this end, mental states and thought processes are physical.”

Source: The Doors of Perception & Heaven and Hell

Source: Psyche and Matter (1992), p. 208

The Age of Insight (2012)
Context: I outline in simple terms... our current understanding of the cognitive psychological and neurobiological basis of perception, memory, emotion, empathy, and creativity.... the principles of the viewer's response to art are applicable to all periods of painting.

The Quality You Need Most, from Green Book Magazine (April 1914)

Source: The Nature of Personal Reality (1974), p. 22, Session 614

Source: Address on Laying the Cornerstone of the Bunker Hill Monument (1825), p. 71
Context: Mind is the great lever of all things; human thought is the process by which human ends are ultimately answered; and the diffusion of knowledge, so astonishing in the last half-century, has rendered innumerable minds, variously gifted by nature, competent to be competitors or fellow-workers on the theatre of intellectual operation.

Source: The Nature of the Physical World (1928), Ch. 13 Reality
Context: The mind-stuff is not spread in space and time. But we must presume that in some other way or aspect it can be differentiated into parts. Only here and there does it arise to the level of consciousness, but from such islands proceeds all knowledge. The latter includes our knowledge of the physical world. <!-- p. 277