However little we may like to make the confession in the twentieth century of the Christian era, hatred is a very real power, and there is more of it at work in civilized society than we always recognize. It is, in truth, an abiding element of human nature, and is one of those instincts which we share with the lower animals. "The great cur showed his teeth; and the devilish instincts of his old wolf-ancestry looked out from his eyes, and yawned in his wide mouth and deep red gullet." Oliver Wendell Holmes was describing a dog's savagery; but he would have been the first to admit that an exactly similar spirit may be concealed--and not always concealed--in a human frame. We have lived so long, if not under the domination, still in the profession, of the Christian ethic, that people generally are ashamed to avow a glaringly anti-Christian feeling. Hence the poignancy of the bitter saying: "I forgive him as a Christian--which means that I don't forgive him at all." Under a decent, though hypocritical, veil of religious commonplace, men go on hating one another very much as they hated in Patriarchal Palestine or Imperial Rome. Hatred generally has a personal root. An injury or an insult received in youth may colour the feelings and actions of a whole lifetime. "Revenge is a dish which can be eaten cold"; and there are unhappy natures which know no enjoyment so keen as the satisfaction of a long-cherished grudge. There is an even deeper depravity which hates just in proportion to benefits received; which hates because it is enraged by a high example; which hates even more virulently because the object of its hatred is meek or weak or pitiable. "I have read of a woman who said that she never saw a cripple without longing to throw a stone at him. Do you comprehend what she meant? No? Well, I do." It was a woman who wrote the words. The less abhorrent sort of hatred (if one can discriminate where all is abominable) is the hatred which has no personal root, but is roused by invincible dislike of a principle or a cause. To this type belong controversial hatreds, political hatreds, international hatreds. Jael is the supreme instance of this hatred in action, and it is only fair to assume that Sir Arthur Conan Doyle had this kind of hatred in his mind when he wrote the sentence which I quoted above. But hatred, which begins impersonally, has a dangerous habit of becoming personal as it warms to its work; and an emotion which started by merely wishing to check a wrong deed may develop before long into a strong desire to torture the wrong-doer. Whatever be the source from which it springs, hatred is a powerful and an energetic principle. It is capable, as we all know, of enormous crimes; but it does not despise the pettiest methods by which it can injure its victim. "Hatred," said George Eliot, "is like fire--it makes even light rubbish deadly."