Cosmic Consciousness: A Study in the Evolution of the Human Mind is a 1901 book by the psychiatrist Richard Maurice Bucke, in which the author explores the concept of cosmic consciousness, which he defines as "a higher form of consciousness than that possessed by the ordinary man". In Cosmic Consciousness, Bucke stated that he discerned three forms, or degrees, of consciousness: Simple consciousness, possessed by both animals and mankind Self-consciousness, possessed by mankind, encompassing thought, reason, and imagination Cosmic consciousness, which is "a higher form of consciousness than that possessed by the ordinary man" According to Bucke, Moores said that Bucke's cosmic consciousness is an interconnected way of seeing things "which is more of an intuitive knowing than it is a factual understanding". Moores pointed out that, for scholars of the purist camp, the experience of cosmic consciousness is incomplete without the element of love, "which is the foundation of mystical consciousness". Juan A. Herrero Brasas said that Bucke's cosmic consciousness refers to the evolution of the intellect, and not to "the ineffable revelation of hidden truths". According to Brasas, it was William James who equated Bucke's cosmic consciousness with mystical experience or mystical consciousness. Gary Lachman notes that today Bucke's experience would most likely be "explained" by the so-called "God spot", or more generally as a case of temporal lobe epilepsy, but he is skeptical of these and other "organic" explanations. He regarded Walt Whitman as "the climax of religious evolution and the harbinger of humanity's future". According to Michael Robertson, Cosmic Consciousness and William James's 1902 book The Varieties of Religious Experience have much in common: James popularized the concept of religious experience, which he explored in The Varieties of Religious Experience. He saw mysticism as a distinctive experience which supplies knowledge of the transcendental.