Book excerpt: This book describes the author’s view of how the mind “thinks” at various levels of operation. These levels include nonconscious mind (as in spinal/brainstem reflexes and neuroendocrine controls), subconscious mind, and conscious mind. In the attempt to explain conscious mind, there is considerable critique of arguments over whether or not free will is an illusion. Finally, the author summarizes current leading theories for consciousness (Bayesian probability, chaos, and quantum mechanics) and then presents his own theory based on patterns of nerve impulses in circuits that are interlaced coherently into larger networks.