The Master always insisted that we must learn by ourselves - teach
ourselves -- rather than depend on other people's authority. This had
its limits, of course, as when a bright young fellow was convinced he ought
to try drugs as a means to mysticism -- and "take the risk, for one can
only learn by trial and error."
That moved the Master to tell the old story of the nail and the screw:
"Here is one way to find out whether what you need in a plank is a nail
or a screw: Drive the nail in. If it splits the plank, you know you needed
the screw."