Atrocities are not less atrocities when they occur in laboratories and are called medical research. George Bernard Shaw.  

If slaughterhouses had glass walls, everyone would be a vegetarian. Paul McCartney. 

The greatness of a nation and its moral progress can be judged by the way its animals are treated. Mahatma Gandhi.

People speak sometimes about the “bestial” cruelty of man, but that is  terribly unjust and offensive to beasts, no animal could ever be so cruel as a man, so artfully, so artistically cruel. Fyodor Dostoyevsky.

A day will come in which men will look upon an animal’s murder the same way they look today upon a man’s murder. Leonardo da Vinci. 

If a man can control his body and mind and thereby refrains from  eating animal flesh and wearing animal products, I say he will really be liberated. Gautama Buddha.

The love for all living creatures is the most noble attribute of man. Charles Darwin.

We think of lions and wolves as savage because they kill; but they must kill, or starve. Humans kill other animals for sport, to satisfy their curiosity, to beautify their bodies, and to please their palates. Peter Singer.

Until one has loved an animal a part of one’s soul remains unawakened. Anatole France.

I am in favor of animal rights as well as human rights. That is the way of a whole human being. Abraham Lincoln.