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.
— Albert Schweitzer
Powerful Against Animal Cruelty quotations
I have reached zero tolerance for the cruelty against our animal brothers.
If we are to nuture our culture, let's begin with the animals who have been nothing but our beasts of burden for so long.
The excuse or toleration of cruelty upon any living creature by a woman is a deadly sin against the grandest force in nature - maternal love ... In not a single instance known to science has the cure of any human disease resulted necessarily from this fallacious method of research.

The Queen has done all she could on the dreadful subject of vivisection, and hopes that Mr. Gladstone will speak strongly against such a practice which is a disgrace to humanity.
To be a vegetarian is to disagree - to disagree with the course of things today.
.. starvation, cruelty - we must make a statement against these things. Vegetarianism is my statement. And I think it's a strong one.
The brute animals have all the same sensations of pain as human beings, and consequently endure as much pain when their body is hurt; but in their case the cruelty of torment is greater, because they have no mind to bear them up against their sufferings, and no hope to look forward to when enduring the last extreme pain.

... the only argument against vivisection that will be seen to have lasting power - that we do not improve human society by means that debase human character.
The case against vivisection is the same as that against war and all other forms of cruelty - that violence does not produce long-term solutions.
Animal life, sombre mystery. All nature protests against the barbarity of man, who misapprehends, who humiliates, who tortures his inferior brethren.

Kindness and compassion towards all living things is a mark of a civilized society. Conversely, cruelty, whether it is directed against human beings or against animals, is not the exclusive province of any one culture or community of people.
My own experience has taught me not to underestimate the power of those who protest against cruelty. I'd also say that there may be a tendency to view the animal-rights opposition in somewhat distorted fashion as a new development, as the product of a very recent enlightenment about the rights due to animals.
Shelters, conservationists, those concerned about unnecessary cruelty toward the animals we eat, and people working against species extinction fight to preserve the true riches of our planet, our real inheritance. These are big, critical goals.