On Rewards and Punishments (21-22)

For as the bodies of those men who are only just beginning to recover from a long attack of sickness are very subject to a relapse; so the soul which is just recovering its health finds its intellectual vigour weak and wavering, so that there is room to apprehend that the evil passions may return which were wont to be excited in it by a habit of living in the society of inconsiderate men.

Then, after these contests in which repentance is concerned, he proposes a third class of prizes, relating to justice, which every one who practises obtains a twofold reward; in the first place, that of preservation at the time of general destruction; and secondly, that of being the steward and guardian of every description of animal which is coupled in pairs for the purpose of raising a second stock instead of that which from time to time perishes;