Jean Buridan
c. 1301 – c. 1360 · Paris
A Paris logician and natural philosopher, best remembered for a hungry donkey that does not appear in any of his writings.
Key ideas
Buridan was one of the most important logicians of the Middle Ages, writing on reference, truth and the paradoxes of self-reference, including versions of the liar paradox.
In physics he developed the theory of impetus: a thrown object keeps moving because the thrower gives it an internal force, not because the air pushes it, as Aristotle's followers held. This was a step towards the later idea of inertia.
On the will, he held that when reason judges two options equal, the will can suspend choice and wait for more information. Critics mocked this with the image of a donkey starving between two equal bales of hay, and the image stuck: Buridan's donkey.
Life, briefly
Buridan was born in or near Béthune in northern France and spent his career at the University of Paris, where he served twice as rector. Unusually, he remained a master of arts all his life rather than moving on to theology. Many colourful legends grew up around him, none reliable.
Major works
- Summulae de Dialectica
- Sophismata
- Questions on Aristotle's Physics and Ethics
Appears in
Further reading
- EncyclopediaStanford Encyclopedia of Philosophy: Jean Buridan
- WikipediaJean Buridan