Before you realize this truth, say the Yogis, you will always be in despair, a notion nicely expressed in this exasperated line from the Greek stoic philosopher Epictetus: 'You bear God within you, poor wretch, and know it not.

When a youth was giving himself airs in the Theatre and saying, 'I am wise, for I have conversed with many wise men,' Epictetus replied, 'I too have conversed with many rich men, yet I am not rich!'.