There is another aspect of the subject of heredity and the duties it entails. As the child of long lineage may well inherit much of what was best in his ancestors--fine physique, clear intellect, high moral worth--so also he has his risks. As some one puts it, not all the women have been brave, nor all the men chaste. We know how the tendency to certain forms of disease runs in families. Temper and temperament, moral and physical nature alike, may come down with a taint. An unhappy child may, by some odd freak of nature, appear to have left out the good and taken into him only the unworthy. What can the parents do in such a case? They may not _re_form him--perhaps that is beyond human skill and care, once he has become all that is possible to his nature--but _transform_ him, so that the being he was calculated to become never develops at all; but another being comes to light blest with every grace of which he had only the defect. This brings us to a beneficent law of nature, which underlies the whole subject of early training, and especially so this case of the child whose mother must bring him forth a second time into a life of beauty and harmony. To put it in an old form of words--the words of Thomas à Kempis--what seems to me the fundamental law of education is no more than this: “Habit is driven out by habit.” People have always known that “Use is second nature,” but the reason why, and the scope of the saying, these are discoveries of recent days. A child has an odious custom, so constant, that it is his quality, will be his _character_ if you let him alone; he is spiteful, he is sly, he is sullen. No one is to blame for it; it was born in him. What are you to do with such inveterate habit of nature? Just this; treat it as a bad _habit_, and set up the opposite good habit. Henry is more than mischievous; he is a malicious little boy. There are always tears in the nursery, because, with “pinches, nips, and bobs,” he is making some child wretched. Even his pets are not safe; he has done his canary to death by poking at it with a stick through the bars of its cage; howls from his dog, screeches from his cat, betray him in some vicious trick. He makes fearful faces at his timid little sister; sets traps with string for the housemaid with her water-cans to fall over; there is no end to the malicious tricks, beyond the mere savagery of untrained boyhood, which come to his mother’s ear. What is to be done? “Oh, he will grow out of it!” say the more hopeful who pin their faith to time. But many an experienced mother will say, “You can’t cure him; what is in will out, and he will be a pest to society all his life.” Yet the child may be cured in a month if the mother will set herself to the task with both hands and set purpose; at any rate, the cure may be well begun, and that is half done.