3. And so generally: great truths, practical or ethical, float on the surface of society, admitted by all, valued by few, exemplifying the poet’s adage, “Probitas laudatur et alget,” until changed circumstances, accident, or the continual pressure of their advocates, force them upon its attention. The iniquity, for instance, of the slave-trade ought to have been acknowledged by all men from the first; it was acknowledged by many, but it needed an organized agitation, with tracts and speeches innumerable, so to affect the imagination of men as to make their acknowledgment of that iniquitousness operative. In like manner, when Mr. Wilberforce, after succeeding in the slave question, urged the Duke of Wellington to use his great influence in discountenancing duelling, he could only get from him in answer, “A relic of barbarism, Mr. Wilberforce;” as if he accepted a notion without realizing a fact: at length, the growing intelligence of the community, and the shock inflicted upon it by the tragical circumstances of a particular duel, were fatal to that barbarism. The governing classes were roused from their dreamy acquiescence in an abstract truth, and recognized the duty of giving it practical expression. 4. Let us consider, too, how differently young and old are affected by the words of some classic author, such as Homer or Horace. Passages, which to a boy are but rhetorical commonplaces, neither better nor worse than a hundred others which any clever writer might supply, which he gets by heart and thinks very fine, and imitates, as he thinks, successfully, in his own flowing versification, at length come home to him, when long years have passed, and he has had experience of life, and pierce him, as if he had never before known them, with their sad earnestness and vivid exactness. Then he comes to understand how it is that lines, the birth of some chance morning or evening at an Ionian festival, or among the Sabine hills, have lasted generation after generation, for thousands of years, with a power over the mind, and a charm, which the current literature of his own day, with all its obvious advantages, is utterly unable to rival. Perhaps this is the reason of the medieval opinion about Virgil, as if a prophet or magician; his single words and phrases, his pathetic half lines, giving utterance, as the voice of Nature herself, to that pain and weariness, yet hope of better things, which is the experience of her children in every time.