This work, published in 1901, is the culmination of a lifetime of research and contemplation in which Richard Maurice Bucke (1837-1902) expounds his theory of the development and evolution of consciousness in living things. He uses his own experiences, those of contemporaries such as Tennyson, and of historical figures such as Francis Bacon, as evidence for moments of higher consciousness and intellect known as 'cosmic consciousness'. Bucke's theory is of three states of progressive consciousness, attained through evolution. The Simple Consciousness of animals, Self Consciousness of man to understand his place in the universe, and Cosmic Consciousness, where man might grow to understand the life and order of the cosmos. This pinnacle of understanding is a progression assisted by evolution that Bucke hopes will one day come to all men. A thought-provoking book at any time, full of optimism for the intellectual future of the human race.

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. Whitman, an American poet and journalist described cosmic consciousness as 'ineffable light, light rare, untellable, light beyond all signs, descriptions and languages.' At the age of thirty-five Bucke found himself in this elevated mental state and he describes (in the third person) the manifestations leading up to it; '1. The person, suddenly, without warning, has a sense of being immersed in a flame, or rose-colored cloud, or perhaps rather a sense that the mind is itself filled with such a cloud of haze. 2. At the same instant he is, as it were, bathed in an emotion of joy, assurance, triumph, salvation. 3. Simultaneously or instantly following the above sense and emotional experiences there comes to the person an intellectual illumination quite impossible to describe. Like a flash there is presented to his consciousness a clear conception (a vision) in outline of the meaning and drift of the universe. He does not come to believe merely; but he sees and knows that the cosmos, which to the self conscious mind seems made up of dead matter, is in fact far otherwise-is in very truth a living presence. He sees that instead of men being, as it were, patches of life scattered through an infinite sea of non-living substance, they are in reality specks of relative death in an infinite ocean of life. He sees that the life which is in man is eternal, as all life is eternal; that the soul of man is as immortal as God is; that the universe is so built and ordered that without any peradventure all things work together for the good of each and all; that the foundation principle of the world is what we call love, and that the happiness of every individual is in the long run absolutely certain.' He goes on to say, 'The person who passes through this experience will learn in the few minutes, or even moments, of its continuance more than in months or years of study, and he will learn much that no study ever taught or can teach.' After reading Bucke's writings, P. D. Ouspensky, the respected Russian Philosopher echoed his comments in his book Tertium Organum; 'Cosmic Consciousness is a third form, which is as far above Self Consciousness as is that above Simple Consciousness. The prime characteristic Cosmic Consciousness is, as its name implies, a consciousness of the cosmos, that is, of the life and order of the universe. Along with the consciousness of the cosmos there occurs an intellectual enlightenment or illumination which alone would place the individual on a new plane of existence-would make him almost a member of a new species.'

Richard M. Burke's astonishing treatise on the human mind discusses and attempts to explain mystical experiences in the context of evolutionary change in the brain. During his mid-thirties, Burke underwent a feeling of revelation and felt distinctly enlightened for a short time. Although the period of enlightenment passed, it had an immense impact upon Burke's outlook, steering his personal and professional life in a directions he had never before envisioned. He found the experience a permanent boon to his well-being, and was able to work and enjoy life more than he formerly had. This book attempts to explain the various mystical feelings of enlightenment which humans have experienced over the millennia of recorded history. Burke's opinion is that these phenomena are becoming commoner over time, and represent an evolution of the human mind. He postulates that these experiences will become commoner as centuries go by, and become accepted as an ordinary, then eventually as a necessary part of human life.