The object of the following essay is to set the principle of animals' rights on a consistent and intelligible foot ing, to show that this principle underlies the various efforts of humanitarian reformers, and to make a clear ance of the comfortable fallacies which the apologists of the present system have industriously accumulated. While not hesitating to speak strongly when occasion demanded, I have tried to avoid the tone of irrelevant recrimination so common in these controversies, and thus to give more unmistakable emphasis to the vital points at issue. We have to decide, not whether the practice of fox-hunting, for example, is more, or less, cruel than vivisection, but whether all practices which in?ict unnecemary pain on sentient beings are not in compatible with the higher instincts of humanity.