It is natural to most men to suppose that they have enemies and to find a certain fulfillment of their nature when they embark upon a contest. What a man believes upon grossly insufficient evidence is an index to his desires -- desires of which he himself is often unconscious. If a man is offered a fact which goes against his instincts, he will scrutinize it closely, and unless the evidence is overwhelming, he will refuse to believe it. If, on the other hand, he is offered something which affords a reason for acting in accordance with his instincts, he will accept it even on the slenderest evidence. The origin of myths is explained in this way, and much of what is currently believed in international affairs is no better than myth.