The gods in their wisdom have granted us dominion over beasts of burden for two primary purposes. Chief among them, which scarcely needs mentioning, is that Erastil in his kindness saw how we toiled, and sought to lighten our burdens. But just as important is that, by our conduct towards such beasts, we may cultivate virtue, so that we may approach our fellow man in the spirit of goodness.
A man who overburdens his oxen with loads far too weighty, or who demands of his halflings that they harvest all his fields in a single week, wrongs them in so doing. (Such is the folly of vice, for a man who makes a habit of such actions will shortly find that his livestock are no longer fit to work!) But he wrongs himself as well, for in doing so, he twists his soul into a most wretched shape, which must necessarily lead him into ill-treatment of his fellow man. By contrast, a man who asks his oxen to carry only what they can bear, or his halflings to harvest only so much of his crops in a single day as they are capable of, trains in himself the virtues of good temper, good judgment, and compassion, and so will deal with his fellow man the same way.
Likewise, a man who beats his oxen or his halflings bloody for offenses they can scarcely comprehend wrongs such creatures. But more importantly, he inculcates in himself a pernicious habit of cruelty, which will necessarily lead him into cruel conduct towards his fellow man. By contrast, a man who disciplines his beasts only so far as is necessary to ensure proper conduct, but restrains his hand from the cruelest excesses of Asmodianism, grows within himself the seeds of magnanimity and justice, and so will behave magnanimously and justly towards his fellow man.
There are those who argue that it would be better to simply turn all such beasts free, lest the temptation to mistreat them drive us back into pernicious habits. To this I say that, if there is truly any man so intemperate that the very possession of such creatures leads him into vice, such a man ought of course to sell or gift them to a more righteous owner — and then perhaps to seek out a hermitage, lest he treat his fellow man in the same way. But as for the bulk of men, such a suggestion has little merit. For a man cannot grow in virtue merely by contemplating it, but only by conducting himself virtuously. The gods have given us a gift; let us not waste it.