Well and good. At a pinch one can live like that. But the words pity, kindness, love of one's neighbour do not occur in Ulpian's pithy statements, and the Law knows nothing of them.
The Law guards each man's well-earned possessions, but it bids no one make sacrifices. Morality can demand these. It can insist that the individual should freely, and urged by his own inner impulse, impose sacrifices upon himself, reduce his possessions in favour of another, disturb his personal comfort at any moment, perhaps even risk his life; that is to say, that of his own free will he should do just those things from which the Law carefully shields him. Where the Law says: injure no one! Morality says often enough: injure yourself to do good to your neighbour. Where the Law says: to each man his own! Morality not seldom says: to each man your own if he needs it more than you do. Morality counts on the existence of a quality of which the Law has no need: Sympathy. To be moral we must feel in our own being at the time, or retrospectively, the subjective experiences of our neighbour, with the same quality of emotion that he feels; his pain must be our pain, as his pleasure must be our pleasure. For the man who cannot do this--who realizes in his mind the circumstances of his neighbour only as an image, and without the concomitant note of feeling--it is impossible to rise to the height of Morality. It is not his fault, for the gift of sympathy is an organic disposition, which you either do or do not possess, which you can develop or suppress, but which you cannot create if it is lacking. Nevertheless, the lack of sympathy is a pitiable infirmity, for it prevents a man from scaling the heights of Morality.
To respect the Law is to practise a wise selfishness. To act morally is to divest oneself of selfishness and attain the privilege of unselfishness. To behave in strict accordance with the Law earns the merited praise of civic blamelessness. But to act morally is a virtue which is of incomparably higher quality than that of mere blamelessness. The law-abiding man, the honest man, is praised as having been "_Integer vitae sceleris purus_." That is an acceptable epitaph. But the man of active Morality, willingly suffering for others, provides an example which reconciles millions to the hardships of life. The former is a worthy man, but the latter is a saint.