The question is not, Can they reason? nor, Can they talk? But rather, Can they suffer?
-Jeremy Bentham, 19th C Philosopher, Oxford University

The greatness of a nation and its moral progress can be judged by the way its animals are treated.
-Gandhi, The Moral Basis of Vegetarianism

Non-violence leads to the highest ethics, which is the goal of all evolution.
Until we stop harming all other living beings, we are still savages.
-Thomas Edison, Harpers Magazine

It is my view that the vegetarian manner of living, by its purely physical effect on the human
emperament, would most beneficially influence the lot of mankind.
-Albert Einstein, letter to Vegetarian Watch-Tower

While we ourselves are the living graves of murdered beasts,
how can we expect any ideal conditions on this earth?
-George Bernard Shaw

If we believe absurdities, we shall commit atrocities.
-Voltaire

The vegetarian movement ought to fill with gladness the souls of those who have
at heart the realization of God's kingdom upon Earth.
-Leo Tolstoy (author of War and Peace), News Review

Forget the pig is an animal. Treat him just like a machine in a factory.
-Hog Farm Management
 

  But for the sake of some little mouthful of flesh, we deprive a soul of the sun and light, and of that proportion of life and time they had been born to enjoy.
-Plutarch, Moralia

[W]e have discovered chickens literally grown fast to the cage
... the flesh of the toes grew completely around the wire.
-Poultry Tribune

I have no doubt that it is part of the destiny of the human race
in its gradual development to leave off the eating of animals.
-Henry David Thoreau, Walden

People often say that humans have always eaten animals, as if this is a justification for continuing the practice. According to this logic, we should not try to prevent people from murdering other people, since this has also been done since the earliest of times.
-Issac Bashevis Singer, Nobel Laureate

And God said, Behold, I have given you every herb-bearing seed which is upon the face of all the earth, and every tree in which is the fruit of a tree yielding seed: to you it shall be for meat.
-Genesis 1:29

People who let their dogs and cats have litters in order to show their children the "miracle of birth" should come witness the "miracle of death" performed in the back rooms of animal shelters all over the country.
-Phyllis Wright, Humane Society of the U.S.

Custom will reconcile people to any atrocity.
-George Bernard Shaw, preface to Killing for Sport

The animals of the world exist for their own reasons. They were not made for humans
any more than black people were made for white, or women created for men.
-Alice Walker, author of The Color Purple

The assumption that animals are without rights and the illusion that our treatment of them has no moral significance is a positively outrageous example of Western crudity and barbarity.
Universal compassion is the only guarantee of morality.
-Schopenhauer, On the Basis of Morality

Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it is the
only thing that ever does.
-Margaret Mead

Nothing is more powerful than an individual acting out their conscience,
thus helping bring the collective conscience to life.
-Norman Cousins

To one whose mind is free, there is something even more intolerable in the suffering of animals than in the sufferings of men. For with the latter it is at least admitted that suffering is evil and that the man who causes it is a criminal. But thousands of animals are uselessly butchered every day without a shadow of remorse. If any man were to refer to it, he would be thought ridiculous. And that is the unpardonable crime. That alone is the justification of all that men may suffer. It cries vengeance upon all the human race. If God exists and tolerates it, it cries vengeance upon God.
- Romain Rolland (Nobel Laureate), Jean Christophe

We must fight against the spirit of unconscious cruelty with which we treat the animals. Animals suffer as much as we do. True humanity does not allow us to impose such sufferings on them. It is our duty to make the whole world recognize it. Until we extend our circle of compassion to all living things,
humanity will not find peace.
-Dr. Albert Schweitzer, The Philosophy of Civilization

The day may come when the rest of the animal creation may acquire those rights which never could have been withholden from them but by the hand of tyranny.
-Jeremy Bentham (philosopher)

Life is life--whether in a cat, or dog or man. There is no difference there between a cat or a man. The idea of difference is a human conception for man's own advantage...
-Sri Aurobindo (poet and philosopher)

Non-violence leads to the highest ethics, which is the goal of all evolution. Until we stop harming all other living beings, we are still savages.
-Thomas Edison (inventor)

The time will come when men such as I will look upon the murder of animals as they now look on the murder of men.
-Leonardo Da Vinci (artist and scientist)