“To get up at a regular hour, to devote a regular amount of time during the day to activities such as meditating, reading, listening to music, walking; not to indulge, at least not beyond a certain minimum, in escapist activities like mystery stories and movies, not to overeat or overdrink are some obvious and rudimentary rules. It is essential, however, that discipline should not be practiced like a rule imposed on oneself from the outside, but that it becomes an expression of one’s own will; that it is felt as pleasant, and that one slowly accustoms oneself to a kind of behavior which one would eventually miss, if one stopped practicing it.”