There are some things about which we must be pessimistic, and others about which we must be optimistic, and both are necessary in life. If someone says, "Your friend is unkind to you, he does not love you, he is not a true friend to you," and we keep an unbelieving attitude towards this criticism, this criticism will remain negative, and will have no effect either upon us or upon our friend; whereas if we believe it, our belief in time will allow the same attribute to manifest in our friend. When a man says, "I am going to fight, but I doubt if we shall win," he had better not fight; but the one who notices all the signs which show that there cannot be a victory and yet feels that he will succeed, will surely win in the end.