Galen

Abstract

Galen’s contributions are De semine (Works 1490; separately 1533), De foetuum formatione (1535 and in French 1559) and De usu partium (1528 and in French 1566). Galen opposes Aristotle on four points especially: the existence of female semen; the material constitution of the embryo; the role of the testes (which for Aristotle had no part in forming semen); and the choice of the liver, rather than the heart, as the earliest centre of foetal development. These points of difference are central to academic debate in the Renaissance. In De semine Galen speaks of the operations of heat and spirit. In part this recalls the Hippocratic pneuma, and the activities of the physical qualities – hot, cold, moist and dry – which Galen says form the simple parts. But the spirit appears to do more, intelligently arranging and composing the parts. If pressed on the nature of the essence lying behind this formative faculty, Galen is willing to say that it clearly reveals intelligence, but not to speculate on whether this essence, or soul, is mortal or immortal, corruptible or incorruptible, unitary or existing in parts. The result is a system which is far from logical.