Sentence:  Since either haystack is better than starvation, and since neither haystack is known to be worse than the other, <WSD>Buridan's ass</WSD> has a good reason to choose either. Suppose it chooses haystack A, rejecting haystack B as well as starvation. 
Meaning of the word marked with <WSD> tags:  The hypothetical donkey, as a typical character of a number of philosophical paradoxes involving equally valuable incentives to action, and the nature of the possible choices and outcomes.