John Kenneth Galbraith, the Canadian economist, invented the phrase “the conventional wisdom” (CW), pseudofacts that everyone knew to be true, were hardly ever questioned but which, when challenged were often not evidence based. Medical textbooks are full of such CWs.

Differentiating between sharp and blunt appreciation? Simple. The CW is to ask the patient “Is this sharp or blunt?” when administering a sharp or blunt stimulus. Er, no. Differentiation can be quite difficult. Have you tried it on your own feet? A more useful question is to ask, when alternating a sharp and blunt stimulus, “Is there any difference between these?”

The CW when testing for cerebellar intention tremor in the arms is to use the finger …