"No League of Nations, or of individuals, can avail, without a change of heart. Reformers of all classes must recognize that it is useless to preach peace by itself, or socialism by itself, or anti-vivisection by itself, or vegetarianism by itself, or kindness to animals by itself. The cause of each and all of the evils that afflict the world is the same the general lack of humanity, the lack of the knowledge that all sentient life is akin, and that he who injures a fellow-being is in fact doing injury to himself. The prospects of a happier society are wrapped up in this despised and neglected truth, the very statement of which, at the present time, must appear ridiculous to the accepted instructors of the people."

“Have the lower animals "rights?" Undoubtedly—if men have.”

“The emancipation of men from cruelty and injustice will bring with it in due course the emancipation of animals also. The two reforms are inseparably connected, and neither can be fully realized alone.”

“I shall die ... as I have lived, rationalist, socialist, pacifist, and humanitarian.”

“Religion has never befriended the cause of humaneness. Its monstrous doctrine of eternal punishment and the torture of the damned underlies much of the barbarity with which man has treated man; and the deep division imagined by the Church between the human being, with his immortal soul, and the soulless "beasts", has been responsible for an incalculable sum of cruelty.”

“And, after all, the humane spirit, which is the motive power of all true schemes of reform, is, by its very essence, independent of belief in what is commonly called "success." We work for an ideal, not because we believe the ideal is destined to be triumphant, but because we are impelled so to work, and cannot, without violence to our best instincts, act otherwise. We protest against cruelty and injustice for the same reason, not merely because we feel that the dawn of a better day is at hand, but because such a protest has to be made, and we know intuitively that we must help to make it. Of the event we can have no absolute assurance—it rests for other minds and other hands than our—but we can at least be assured that we have done what was natural and inevitable to us, and that, whether successful or unsuccessful, there was no other course for a thoughtful man to take.”

“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 inflict unnecessary pain on sentient beings are not incompatible with the higher instincts of humanity.”