Cosmic Consciousness: A Study in the Evolution of the Human Mind is Richard Bucke's theory that our mental states are evolving and that to date we have experienced three stages in the development of consciousness: the 'simple consciousness' of animals, the 'self-consciousness' of the vast majority of humans (reason, self awareness, imagination, etc.), and in some cases 'cosmic consciousness'; a mystical state of being beyond 'self consciousness' and the next stage of human development.

Bucke hypothesized that 'cosmic consciousness' is slowly beginning to appear in humans and will eventually spread widely throughout the human race. He posited that certain notable individuals throughout history have demonstrated that they have attained 'cosmic consciousness'.

In the book he cites examples such as Jesus, Buddha, Mohammed, Dante, St Paul, Francis Bacon, William Blake, and his close friend Walt Whitman.