The physical evolution of conciousness
"The brain is a physical organ—that much is clear to everyone. But how do we understand the mind and consciousness—what is it and how did it evolve?
Do you think of yourself as having a brain or being a brain? Can you conceive of your mind, your personality, your self, as entirely and only the product of your physical brain? The mind seems non-physical, ethereal and spiritual. The intuitive sense that mind and brain are separate entities can be hard to shake. But, what we know from science is that the mind comes from the brain and nothing but the brain. The mind is what the brain does. Any theory that does not begin with this assumption would necessarily imply that practically all the rest of modern science is fundamentally incorrect.
The physical basis of consciousness is a guiding principle behind a great many practical and effective treatments for mental illnesses. Daily, I witness the subtle or dramatic effects of varying degrees of disturbance of brain functioning on the ‘mind’ or ‘personality.’ I also witness the beneficial cognitive, emotional, and behavioral effects of physically based medical treatments[i]. There is no aspect of the mind, the personality, the ‘self,’ or the ‘will’ that is not completely susceptible to chemical influences or physical diseases that disrupt neuronal circuitry."