[30] But the seventh power is that which proceeds from the dominant mind, which is more glorious than the other six powers, and which has by preeminent vigour obtained the mastery over them all, and when that retires, choosing solitude, and its own society, and living by itself, as one that has no need of any other, and that is all-sufficient for itself, being then emancipated from the cares and troubles that are found in the human race, embraces a calm and tranquil life.