text: But the study of philosophy is not to be postponed until you have leisure; everything else is to be neglected in order that we may attend to philosophy, for no amount of time is long enough for it, even though our lives be prolonged from boyhood to the uttermost bounds of time allotted to man. It makes little difference whether you leave philosophy out altogether or study it intermittently; for it does not stay as it was when you dropped it, but, because its continuity has been broken, it goes back to the position in which it was at the beginning, like things which fly apart when they are stretched taut. We must resist the affairs which occupy our time; they must not be untangled, but rather put out of the way. Indeed, there is no time that is unsuitable for helpful studies; and yet many a man fails to study amid the very circumstances which make study necessary. He says: "Something will happen to hinder me." No, not in the case of the man whose spirit, no matter what his business may be, is happy and alert. It is those who are still short of perfection whose happiness can be broken off; the joy of a wise man, on the other hand, is a woven fabric, rent by no chance happening and by no change of fortune; at all times and in all places he is at peace. For his joy depends on nothing external and looks for no boon from man or fortune. His happiness is something within himself; it would depart from his soul if it entered in from the outside; it is born there. Sometimes an external happening reminds him of his mortality, but it is a light blow, and merely grazes the surface of his skin. Some trouble, I repeat, may touch him like a breath of wind, but that Supreme Good of his is unshaken. This is what I mean: there are external disadvantages, like pimples and boils that break out upon a body which is normally strong and sound; but there is no deep-seated malady. The difference, I say, between a man of perfect wisdom and another who is progressing in wisdom is the same as the difference between a healthy man and one who is convalescing from a severe and lingering illness, for whom "health" means only a lighter attack of his disease. If the latter does not take heed, there is an immediate relapse and a return to the same old trouble; but the wise man cannot slip back, or slip into any more illness at all. For health of body is a temporary matter which the physician cannot guarantee, even though he has restored it; nay, he is often roused from his bed to visit the same patient who summoned him before. The mind, however, once healed, is healed for good and all.