Contrary to the generally accepted theory the will is not the invincible force it is claimed to be; in fact, whenever imagination and will come into conflict it is always imagination that triumphs. Try to do something while you are repeating: "I cannot do it," and you will see this truth confirmed. The mere idea of inability to accomplish a thing paralyzes the will power.

Chapter II. The role of imagination : About the "Dominance of the imagination over the will". - Autosuggestion : My method (1923)