Independence is achieved by indifference. It does not mean that one should take no heed of what anyone does or says; it only means one should discriminate between important and unimportant things of everyday life; that every necessary and unnecessary thing should not demand so much of one's attention, thought, and feeling. Political economy has become a subject of education, but spiritual economy is the main thing in religion. All one says and does and all that one thinks and feels puts a certain strain upon one's spirit. It is wise to avoid every risk of losing one's equilibrium. One must stand peacefully but firmly before all influences that disturb one's life. The natural inclination is to answer in defence to every offence that comes from outside, but in that way one loses one's equilibrium. Self-control, therefore, is the key to all success and happiness.