Buridan’s ass

Although it bears his name, the medieval philosopher Jean Buridan did not invent this paradox, which probably originated as a parody of his theory of free will, according to which human freedom consists in the ability to defer for further consideration a choice between two apparently equally good alternatives (the will is otherwise compelled to choose what appears to be the best). Imagine a hungry donkey who is placed between two equidistant and identical bales of hay. Assume that the surrounding environments on both sides are also identical. The donkey cannot choose between the two bales and so dies of hunger, which is absurd. The paradox was later thought to constitute a counterexample to Leibniz’s principle of sufficient reason, one version of which states that there is an explanation (in the sense of a reason or cause) for every contingent event. Whether the donkey chooses one bale or the other is a contingent event, but there is apparently no reason or cause to determine the donkey’s choice. Yet the donkey will not starve. Leibniz, for what it is worth, vehemently rejected the paradox, claiming that it was unrealistic.