The American writer Carl Zimmer has written a brilliant book on Thomas Willis (1621-75), the founder of neurology. Willis discovered the human brain's role and importance, and was the first to examine how it worked.
Willis was part of the remarkable generation of Britons who founded the Royal Society, aiming to understand the physical world: William Harvey, who by discovering the circulation of the blood had, as Willis said, created `a new foundation of medicine', Christopher Wren, Robert Hooke, Robert Boyle and William Petty, whom Karl Marx called the father of political economy.
To keep the Restoration Stuart state on side, they excluded from the Society the materialist Thomas Hobbes, who had said that the mind was `matter in motion'. As the Platonist Henry More realised, `No spirit, no God'.
Willis' book `The Anatomy of the Brain and Nerves' mapped the brain, and was the first unified treatment of the brain and the nerves. The new science combined anatomical study of the human brain with comparisons to animal brains, experiments and medical observations. He identified the loop of arteries that supplies the brain, which became known as the Circle of Willis. The 20th century neurologist Lord Brain described Willis as `the Harvey of the nervous system'.
Willis "created a material explanation of the soul and its disorders. ... He had transformed the traditional three-part soul, which had existed since Plato, into the corpuscular chemistry of the nervous system. The soul was not just moved to the brain but limited to it, and only through the nerves could it experience the world."
But the idealist philosopher John Locke attacked Willis' materialist approach, holding back neurology's development. Zimmer explains, "Locke also influenced the way philosophers pondered the mind itself. He dismissed details of neurology and concerned himself with ideas and how they fit together, and generations of philosophers followed his lead. It would take neurologists 150 years to show that Willis was right, that studying the anatomy and chemistry of the brain can indeed reveal the workings of the mind, that they can map the geography of passion, reason, and memory."