When you have thrown a stone, you cannot afterwards bring it back again, but nevertheless you are responsible for having taken up the stone and flung it, for the origin of the act was within you. Similarly the unjust and profligate might at the outset have avoided becoming so, and therefore they are so voluntarily, although when they have become unjust and profligate it is no longer open to them not to be so.
Moral virtue is a mean . . . between two vices, one of excess and the other of defect; . . . it is such a mean because it aims at hitting the middle point in feelings and in actions. This is why it is a hard task to be good, for it is hard to find the middle point in anything.
Greatness of Soul seems therefore to be as it were a crowning ornament of the virtues; it enhances their greatness, and it cannot exist without them. Hence it is hard to be truly great-souled, for greatness of soul is impossible without moral nobility.
Conscientious and careful physicians allocate causes of disease to natural laws, while the ablest scientists go back to medicine for their first principles.
Money was established for exchange, but interest causes it to be reproduced by itself. Therefore this way of earning money is greatly in conflict with the natural law.