It does not require any direct, or even indirect, inculcation of _opinion_ on the teacher’s part to do mischief. It is the contagion of his emotions which is to be feared, if those emotions be base or bad. Let him teach History and betray his enthusiasm for selfish and sanguinary conquerors, or justify assassins and anarchists, or jest—Gibbon fashion—at martyrs and heroes, will he not communicate those base sentiments to his young audience? Or let him teach Science, and convey to every student’s mind that deification of mere knowledge, that insolent sense of superiority in the possession of it, that remorseless determination to pursue it regardless of every moral restraint, which is too often the “note” of modern scientism, will the instruction he affords to his students’ brains counterbalance the harm he will do to their hearts? And, on the other hand, what a splendid vantage-ground for the dissemination not merely of knowledge, but of elevated feelings, is that of a Teacher! Merely in teaching a dead or modern language, a fine-natured man communicates his own glowing feelings respecting the masterpieces of national literature which it is his duty to expound. The last point we need notice as regards the contagion of emotions among the young is the subject of Companions. Here again, as in the case of respect for mothers, there is great unanimity in theory. Every one admits that bad companions are ruinous for boys or girls. But, when it comes to taking precautions against the herding of innocent and well-nurtured children with others who have been familiar with vice, I see little trace of the anxious care and discrimination which ought to prevail. Nay, in the case of the children of the poor, it seems to me the law is often wickedly applied to compel good parents to send them, against their own will and convictions, to sit beside companions who have come straight to school out of slums of filth, moral and physical. I have known Americans argue that it is right for children of all classes to associate together, so that the well-trained may communicate good ideas to the ill-trained. The reasoning appears to be on a par with a proposal to send healthy people to sleep in a cholera hospital. But, while we allow ourselves to be terrified beyond bounds by alarms about the infection of bodily disease, we take hardly any precautions against the more dreadful, and quite as real, infection of moral corruption.[10]