Those who are enamoured of practice without science are like a pilot who goes into a ship without rudder or compass and never has any certainty of where he is going. Practice should always be based upon a sound knowledge of theory.
You will never have a greater or lesser dominion than that over yourself. . . . the height of a man's success is gauged by his self-mastery; the depth of his failure by his self-abandonment. . . . And this law is the expression of eternal justice. He who cannot establish dominion over himself will have no dominion over others.