What can we Learn from Buridan's Ass?

I Introduction

The mythical¹ hungry ass, facing two identical bundles of hay equidistant from him, has engendered two related questions. Can he choose one of the bundles, there seemingly being nothing to incline him one way or the other? If he can, the second puzzle — pertaining to rational choice — arises. It seems the ass cannot rationally choose one of the bundles, because there is no sufficient reason for any choice.²

In what follows, I will argue that choice is possible even when there is no option which is better than the others (section II), and that it is perfectly reasonable to choose an option even when there is no sufficient reason for it (section III). I will then (section IV) point to another puzzling feature of the ass's tale, a seeming difference between it and its theoretical analogue, and consider some suggestions as to how the asymmetry is to be explained (section V).

II Can the Ass Choose?

Lloyd Strickland thinks that choosing arbitrarily between the bundles is unintelligible, since 'the will [would] be moved without any reason(s) whatsoever' (2006, 150). But whether he has in mind normative reasons or motivating reasons, the claim is confused. The ass is not choosing without any reason. There is no normative reason for choosing the bundle on the right rather than the one on the left (or vice versa), and perhaps there is no motivating reason either. But there is a very good (motivating and normative) reason for choosing either bundle (instead of starving).

Some claim that opting for an option without a sufficient reason is not a genuine choice even if performed for a reason. Thus, Al-Ghazâlî puts the following argument in the mouth of his (Aristotelian) opponents, who think even God can only act on sufficient reasons:

Unless God had a reason for His choice [to create the world as and when He did], it was not choice: it was something of which we have no conception whatever, and calling it a choice is merely throwing dust in our own eyes ... choice is choice between alternatives ... [and] one must in some way present itself as more attractive than the other, or it cannot be chosen.³

Averroes, in a similar vein, suggests that 'distinguishing [i.e. choosing] one from the other means giving a preference to one over the other,'⁴ and Collingwood (1960, 41) agrees: 'Choice is choice between alternatives, and ... one must in some way present itself as more attractive than the other, or it cannot be chosen.'

The claim that choice in the absence of a sufficient reason is a conceptual impossibility can be summarily dismissed. Choice conceptually requires the existence of more than one alternative (McAdam, 1965), and arguably — the existence of a reason. Perhaps 'arbitrary choice' is an oxymoron (Raz, 1999; Strickland, 2006, 150),⁵ but this has no bearing on the ass's situation.

Even if it is conceptually possible to choose without a sufficient reason, such a choice, some argue, is metaphysically or nomologically impossible. Thus, Aristotle suggests that 'the man who is violently but equally hungry and thirsty, and stands at an equal distance from food and drink ... must remain where he is.'⁶ 'If two things are absolutely equal,' Aquinas concurs, 'man is not moved to one more than to the other; thus, if a hungry man ... be confronted on either side with two portions of food equally appetizing and at an equal distance, he is not moved towards one more than to the other.'⁷ 'In things which are absolutely indifferent,' Leibniz says, 'there can be no choice and consequently no election or will, since choice must have some reason or principle.'⁸

Spinoza will 'entirely grant that if a man were placed in such a state of equilibrium he would perish of hunger and thirst, supposing he perceived nothing but hunger and thirst, and the food and drink were equidistant from him' (1677, part 2, final Scholion), and more recently, Manor says that 'Given that the ass is placed in equal distance from two completely identical hay...