It has pleased Chrysippus to define a slave as “a hireling for life.” Just as a hireling bestows a benefit when he does more than he engaged himself to do, so when a slave’s love for his master raises him above his condition and urges him to do something noble — something which would be a credit even to men more fortunate by birth — he surpasses the hopes of his master, and is a benefit found in the house. Do you think it is just that we should be angry with our slaves when they do less than their duty, and that we should not be grateful to them when they do more? Do you wish to know when their service is not a benefit? When the question can be asked, “What if he had refused to do it?” When he does that which he might............