Philosophy is essentially a middle-aged man’s game, though certain philosophers (notably Plato and Kant) have put up their best performances when they were well past middle life. Those of us who are not Platos or Kants are well advised to retire gracefully before they have too obviously lost their grip. Medical science would almost have made the world safe for senility, if physics had not made it unsafe for everybody; and there are far too many old clowns arthritically going through their hoops, to the embarrassment of the spectators: From X’s eyes the streams of dotage flow,And Y expires a driveller and a show.

C. D. Broad, A reply to my critics, in Paul A. Schilpp (ed.) The philosophy of C.D. Broad, New York, 1959, pp. 711–830, pp. 711-830