It is abundantly evident, both from history and from present experience, that the instinctive shock, or natural feeling of disgust, caused by the sight of the sufferings of men is not generically different from that which is caused by the sight of the sufferings of animals. The latter, to those who are not accustomed to it, is intensely painful. The former continually becomes by use a matter of absolute indifference. If the repugnance which is felt in the one case appears greater than in the other, it is not on account of any innate sentiment which commands us to reverence our species, but simply because our imagination finds less difficulty in realising human than animal suffering, and also because education has strengthened our feelings in the one case much more than in the other. There is, however, no fact more clearly established than that when men have regarded it as not a crime to kill some class of their fellow-men, they have soon learnt to do so with no more natural compunction or hesitation than they would exhibit in killing a wild animal. This is the normal condition of savage men. Colonists and Red Indians even now often shoot each other with precisely the same indifference as they shoot beasts of prey, and the whole history of warfare—especially when warfare was conducted on more savage principles than at present—is an illustration of the fact. Startling, therefore, as it may now appear, it is in no degree unnatural that Roman spectators should have contemplated with perfect equanimity the slaughter of men. The Spaniard, who is brought in infancy to the bull-ring, soon learns to gaze with indifference or with pleasure upon sights before which the unpractised eye of the stranger quails with horror, and the same process would be equally efficacious had the spectacle been the sufferings of men.