The Body in the Renaissance: From Empiricism to Science
The battleground of the Renaissance, among other things, manifested itself in the need to know how a human body was really constituted: a curiosity shared by artists, learned people, and physicians alike. The Church required that people accept that all that could be known about the body had been written by Aristotle, Galen, and the Bible. Those who only referred to Aristotle were called Peripaticians. All the same, most physicians knew to what extent this knowledge was limited and that it did not allow for the care of the suffering that confronted them Artists, physicians, and philosophers had organized a large clandestine network to make anatomical observation of stolen cadavers and the mutual exchange of their observations possible. Galileo recounts an anecdote about the debate between a Humanist and Peripatetic physicians:
It happened on this day that he [an anatomist from Venice] was investigating the source and origin of the nerves, about which there exists a notorious controversy between the Galenist and Peripatetic doctors. The anatomist showed that the great trunk of nerves, leaving the brain and passing through the nape, extended on down the spine and then branched out through the whole body, and that only a single strand as fine as a thread arrived at the heart. Turning to a gentleman whom he knew to be a peripatetic philosopher, and on whose account he had been exhibiting and demonstrating everything with unusual care, he asked this man whether he was at last satisfied and convinced that the nerves originated in the brain and not in the heart. The philosopher, after considering for a while, answered: You have made me see this matter so plainly and palpably that if Aristotle’s text were not contrary to it, stating clearly that the nerves originate in the heart, I should be forced to admit it to be true.â (Galileo, Dialogue Concerning the Two Chief World Systems, 1630, II, p. 108)
The Peripatetic teachers of the day defended the theory that diverse organs were the seat of various psychic propensities: the liver for passions, the brain for judgments, and the heart for affects.4 Peripatetic physicians assumed that there are connections between the mind and the organs that do not pass through the soul.
The idea that knowledge must be compatible with what is observable is referred to as empiricism. If that is all there had been to their endeavors, Galileo and his colleagues would have met the criterion of empiricists but not that of scientists. This generation of thinkers searches for rigorous observations and most of all for laws; that is, a theoretical construct that describes the mechanisms that organize what is observed. This combination makes Galilean physics a science. He postulates that the entire universe organizes itself coherently by following a logic that is close to what mathematics and geometry describe. This logic can be used to analyze all observed phenomena and all phenomena that will be observed. This idea could have been a theory only as interesting as all of the others, if it had not revealed itself particularly fruitful, easy to teach, and easy to disseminate. Furthermore this theory could be improved upon by constant research.