From the Foreword: The problem of life consists in learning how to live. It is like the problem of addition or subtraction to the schoolboy. When mastered, all difficulty disappears, and the problem has vanished. All the problems of life, whether they be social, political, or religious, subsist in ignorance and wrong-living. As they are solved in the heart of each individual, they will be solved in the mass of men. Humanity at present is in the painful stage of “learning.” It is confronted with the difficulties of its own ignorance. As men learn to live rightly, learn to direct their forces and use their functions and faculties by the light of wisdom, the sum of life will be correctly done, and its mastery will put an end to all the “problems of evil.” To the wise, all such problems have ceased.

Man is the maker of happiness and misery. Further, he is the creator and perpetuator of his own happiness and misery. These things are not externally imposed; they are internal conditions. Their cause is neither deity, nor devil, nor circumstance, but Thought. They are the effects of deeds, and deeds are the visible side of thoughts. Fixed attitudes of mind determine courses of conduct, and from courses of conduct come those reactions called happiness and unhappiness. This being so, it follows that, to alter the reactive condition, one must alter the active thought. To exchange misery for happiness it is necessary to reverse the fixed attitude of mind and habitual course of conduct which is the cause of misery, and the reversed effect will appear in the mind and life. A man has no power to be happy while thinking and acting selfishly; he cannot be unhappy while thinking and acting unselfishly. Wheresoever the cause is, there the effect will appear. Man cannot abrogate effects, but he can alter causes. He can purify his nature; he can remould his character. There is great power in self-conquest; there is great joy in transforming oneself....