"When we are in doubt whether an action is good or bad, abstain from it."

Next Quote

If you are leaping a ravine, the moment of takeoff is a bad time for considering alternative strategies... Do it in the 'closed' mode. But the moment the action is over, try to return to the 'open' mode... because in that mode we are the most aware, most receptive, most creative, and therefore at our most intelligent.

— John Cleese