To the end of his days he never published the secret of his art.

Lao Ch'êng Tzŭ returned home, and for three months pondered deeply over the words of the Venerable Yin Wên. Subsequently, he had the power of appearing or disappearing at will; he could reverse the order of the four seasons, produce thunderstorms in winter and ice in summer, make flying things creep and creeping things fly. But to the end of his days he never published the secret of his art, so that it was not handed down to after generations.