INTRODUCTION: FOURTEENTH-CENTURY PHYSICS

The fourteenth century saw the emergence of a new trend in medieval philosophy and science. While continuing to adhere generally to an Aristotelian understanding of nature, Christian scholars began to question and modify certain premises of Aristotelian physics and to suggest non-Aristotelian alternatives, reviving pre-Socratic or Hellenistic views and developing original ideas based on observation and experience. Such remarkable figures as Thomas Bradwardine and his successors in Oxford, and Jean Buridan and his students in Paris challenged basic Aristotelian tenets about infinity, place, vacuum, motion, and material substance, suggesting the possibility of an infinite cosmos filled by multiple worlds. Although motivated largely by Christian doctrine and the condemnations of Aristotle, this move towards critical inquiry led to a new conception of the universe, which anticipated and contributed to the scientific revolution of the sixteenth and seventeenth centuries.

The outstanding Jewish representative of this critical trend in European philosophy was Hasdai Crescas (c. 1340–1410/11), legal scholar, communal leader, and courtier in Barcelona and Saragossa. Perhaps influenced by the Paris physicists, and motivated by similar theological interests, Crescas in his Light of the Lord subjected Maimonides’ summary of Aristotelian physics to a searching attack. Unlike his Christian counterparts, however, Crescas was not content merely to speculate about problem areas within a generally coherent natural science.