Jean Buridan (byʁidɑ̃; Latin: Johannes Buridanus; 1301 – 1359/62) was an influential 14thcentury French philosopher. Buridan taught in the faculty of arts at the University of Paris for his entire career and focused in particular on logic and on the works of Aristotle. Buridan sowed the seeds of the Copernican Revolution in Europe. He developed the concept of impetus, the first step toward the modern concept of inertia and an important development in the history of medieval science. His name is most familiar through the thought experiment known as Buridan's ass, but the thought experiment does not appear in his extant writings. Buridan was born sometime before 1301, perhaps at or near the town of Béthune in Picardy, France, or perhaps elsewhere in the diocese of Arras. He received his education in Paris, first at the Collège du Cardinal Lemoine and then at the University of Paris, receiving his Master of Arts degree and formal license to teach at the latter by the mid-1320s. Unusually, he spent his entire academic life in the faculty of arts, rather than obtaining the doctorate in law, medicine or theology that typically prepared the way for a career in philosophy. Also unusual for a philosopher of his time, Buridan further maintained his intellectual independence by remaining a secular cleric, rather than joining a religious order. A papal letter of 1330 refers to him as simply, "clericus Atrebatensis diocoesis, magister in artibus [a cleric from the Diocese of Arras and Master of Arts]." As university statutes permitted only those educated in theology to teach or write on the subject, there are no writings from Buridan on either theological matters or commentary of Peter Lombard's Sentences. Speculation on his reasons for avoiding religious matters have remained uncertain. Most scholars think it is unlikely that he went unnoticed, given his philosophical talents. As well, it is unlikely that he could not afford to study theology, given that he received several bursaries and stipends.