Thought is not just something subjective in our heads, says early Theosophist, Annie Besant. Thought is power, real, objective power. Moreover, the thoughts we create have a life of their own. They have a kind of material reality that affect other people for good or ill. So, is our responsibility to choose. Teaching us to use the power of thought well, is the purpose of this metaphysical book. Leading contemporary Theosophists have added practical exercises and modernized Besant's language to make her timeless truths accessible for learning.