To know what question one should, reasonably, ask is already a great and necessary proof of one's sagacity and insight. For if the question is in itself absurd and demands answers that are unnecessary, then it not only embarrasses the person raising it, but sometimes has the further disadvantage of misleading the incautious listener: it may prompt him to give absurd answers and to provide us with the ridiculous spectacle (as the ancients said) one person milks the ram while the other holds a sieve underneath."*
*Reference works characterize this saying as a Greco-Roman proverb quoted (e.g.) in Sameul Hieron, Works (1616), i, 586; and in John Hales, Several Tracts (1656), 40. Milking of rams is mentioned also in Vergil's Eclogues, iii, 91.