Book 6.5

Though you have bestowed a benefit upon me, yet you have since done me a wrong; the benefit demanded gratitude, the wrong required vengeance: the result is that I do not owe you gratitude, nor do you owe me compensation--each is cancelled by the other. When we say, "I returned him his benefit," we do not mean that we restored to him the very thing which we had received, but something else in its place. To return is to give back one thing instead of another, because, of course, in all repayment it is not the thing itself, but its equivalent which is returned. We are said to have returned money even though we count out gold pieces instead of silver ones, or even if no money passes between us, but the transaction be effected verbally by the assignment of a debt.

I think I see you say, "You are wasting your time; of what use is it to me to know whether what I do not owe to another still remains in my hands or not? These are like the ingenious subtleties of the lawyers, who declare that one cannot acquire an inheritance by prescription, but can only acquire those things of which the inheritance consists, as though there were any difference between the heritage and the things of which it consists. Rather decide this point for me, which may be of use. If the same man confers a benefit upon me, and afterwards does me a wrong, is it my duty to return the benefit to him, and nevertheless to avenge myself upon him, having, as it were, two distinct accounts open with him, or to mix them both together, and do nothing, leaving the benefit to be wiped out by the injury, the injury by the benefit? I see that the former course is adopted by the law of the land; you know best what the law may be among you Stoic philosophers in such a case. I suppose that you keep the action which I bring against another distinct from that which he Strings against me, and the two processes are not merged into one? For instance, if a man entrusts me with money, and afterwards robs me, I shall bring an action against him for theft, and he will bring one against me for unlawfully detaining his property?"