Pliny, who corresponded with the emperor Trajan, and whose name is familiar to the student of Christian Evidences, exhorted parents to take a deep interest in the education of their children. He largely endowed an institution in his native town of Como, for the assistance of the children of the poor. His humanity was extended to slaves. He treated his own with great kindness, allowing them to dispose of their own earnings, and even to make wills. Of masters who had no regard for their slaves, he said, "I do not know if they are great and wise; but one thing I do know, they are not men." Dion Chrysostom, another Stoic, plainly declared that slavery was an infringement of the natural rights of men, who were all born for liberty; a dictum which cannot be paralleled in any part of the New Testament. It must be admitted, indeed, that Paul, in sending the slave Onesimus back to his master Philemon, did bespeak humane and even brotherly treatment for the runaway; but he bespoke it for him as a Christian, not simply as a man, and uttered no single word in rebuke of the institution of slavery. Plutarch's humanity was noble and tender. "The proper end of man," he said, "is to love and to be loved." He regarded his slaves as inferior members of his own family. How strong, yet how dignified, is his condemnation of masters who sold their slaves when disabled by old age. He protests that the fountain of goodness and humanity should never dry up in a man. "For myself," he said, "I should never have the heart to sell the ox which had long labored on my ground, and could no longer work on account of old age, still less could I chase a slave from his country, from the place where he has been nourished for so long, and from the way of life to which he has been so long accustomed." Sentiments like these were the natural precursors of the abolition of slavery, as far as it could be abolished by moral considerations.