The whole secret of esotericism lies in controlling the mind and in working with it as an artist would work on a canvas, producing whatever he likes. When we are able to produce on the canvas of our heart all that we wish, and to erase all we wish, then we arrive at that mastery for which our soul craves.

Hazrat Inayat Khan, The Heart of Sufism by H. J. Witteveen, editor