Two exactly equal options give no basis for choosing, so a purely rational chooser stalls.
Buridan never wrote it; the example is attributed to him by critics. Real choosers break ties arbitrarily, which is why the paradox is mainly useful for showing that indifference is not the same as inability.
In practice
- A committee with two equally good candidates and no tiebreak rule meets four times and appoints neither.
- Two identical products at the same price sit unbought while a third, slightly worse and clearly different, sells.
- Possible explanations
- The explanation is structural: a decision rule that selects the highest-valued option returns nothing when two options are tied, so something outside the rule, noise or an arbitrary convention, has to break it.
- In its favour
- It isolates a real feature of decision theory, that indifference is not the same as preference, and it is why practical systems build in tie-breakers.
- Against it
- No actual chooser stalls, so the paradox describes a property of a model rather than of behaviour, and the example does not appear in Buridan's writings.
- Standing
- The example does not appear in Buridan's writings; it is an ancient antecedent attributed to him by critics.
- Further reading
- Wikipedia
- Subject
- Decision-making & Reasoning
- Essay
- Paradoxes that broke theories, and sayings that outlived them