THE AMAZING BRAIN – BRAIN EXAMINATION BY GALEN
Centuries later, Galen, a Roman physician who lived in the eastern Mediterranean in the second century of the Christian era, went beyond such mental exercises to test the brain for himself. He took a more hands-on approach and cut the sensory and motor fibers in pigs’ brains to observe the results.
Galen became the first to speculate that particular functions are carried out in specific parts of the brain. Furthermore, as a healer to wounded gladiators, Galen peered into holes rent in human bodies by the violent combat of the arena.
He made rudimentary descriptions of the body’s major organs and fleshed out the description of what he saw as the varieties of human spirit. The liver created desire and pleasure, he said. The heart gave rise to courage and the warmer passions. And the brain contained the rational soul.
Vital spirits swirling in the spaces of the brain carried the spark of human intelligence. He believed they navigated throughout the body via a network of hollow nerve fibers. The brain’s instructions thus moved through tunnels like puffs of wind in pneumatic tubes.
Feelings, understanding, and consciousness arising in the physical structure of the brain? Unseen spirits causing the physical body to move? These were ideas that raised serious questions.
If the qualities of thought that set humans apart from other animals-be it the sense of self, the mind, or the soul- resided in a physical organ, where, exactly, could such thoughts be found? And if thoughts and feelings had no substance, how could they act upon the physical matter of the human body?