Buridan's Ass - History

History

The paradox predates Buridan; it dates to antiquity, being found in Aristotle's On the Heavens. Aristotle, in ridiculing the Sophist idea that the Earth is stationary simply because it is circular and any forces on it must be equal in all directions, says that is as ridiculous as saying that

...a man, being just as hungry as thirsty, and placed in between food and drink, must necessarily remain where he is and starve to death.

— Aristotle, On the Heavens, ca.350 BCE

However, the Greeks only used this paradox as an analogy in the context of discussions of the equilibrium of physical forces.

The 12th century Persian Islamic scholar and philosopher Al-Ghazali discusses the application of this paradox to human decision making, asking whether it is possible to make a choice between equally good courses without grounds for preference. He takes the attitude that free will can break the stalemate.

Suppose two similar dates in front of a man, who has a strong desire for them but who is unable to take them both. Surely he will take one of them, through a quality in him, the nature of which is to differentiate between two similar things.

— Abu Hamid al-Ghazali,The Incoherence of the Philosophers 1100

Moorish Islamic philosopher Averroes (1126-1198), in commentary on Ghazali, takes the opposite view.

Although Buridan nowhere discusses this specific problem, its relevance is that he did advocate a moral determinism whereby, save for ignorance or impediment, a human faced by alternative courses of action must always choose the greater good. In the face of equally good alternatives Buridan believed a rational choice could not be made

Should two courses be judged equal, then the will cannot break the deadlock, all it can do is to suspend judgement until the circumstances change, and the right course of action is clear.

— Jean Buridan, 1340

Later writers satirised this view in terms of an ass which, confronted by both food and water must necessarily die of both hunger and thirst while pondering a decision.