Elementary, my dear Hamish

Although it is not easy to decide definitively who is the most famous doctor in all literature, Doctor Watson must be among the candidates.

This is not to say that he is an entirely plausible character. He is portrayed by his creator—all the more remarkably because his creator was himself a doctor—as a bumbling duffer who never learns from Holmes’s example. Surely there has never been an actual doctor as obtuse as this. Nor could Holmes conceivably have said to any real medical man, as he said to Watson, “You see, but you do not observe.”

Perhaps the most harmless and innocent use to which …