A man is ethical only when life, as such, is sacred to him, that of plants and animals as well as that of his fellowman, and when he devotes himself helpfully to all life that is in need of help.
Albert Schweitzer
To acknowledge that life is valuable does not require the mindless assertion that all life is therefore equivilant.
The love for all living creatures is the most noble attribute of man.
Charles Darwin
To be able to distinguish between the respectful comsumption of a resource and wanton cruelty demonstrates the capacity that seperates him from other life - Reason.
Until he extends the circle of compassion to all living things, man will not himself find peace.
Albert Schweitzer, The Philosophy of Civilization
"In the jungle, the mighty jungle. . . " Sorry, I didn't have anything of substance to say to this one! 
Auschwitz begins whenever someone looks at a slaughterhouse and thinks: they are only animals.
Theodor Adorno (1903-1969), German Marxist philosopher, sociologist, and musicologist
Aushwitz indeed! To assert that animals are equilivilant to humans does not raise their station but rather lowers humanity. The result is not improved treatment of animals but rather a devaluing of human life that can lead to an Aushwitz.
I believe animals should be respected as
citizens of this earth. They should have the right to their own freedom, their own families, and their own life.
John Feldmann, Goldfinger
Citizenship suggests responsibility. Have any of these geniuses had much luck persuading these furry citizens from killing and maiming each other?
As long as people will shed the blood of innocent creatures there can be no peace, no liberty, no harmony between people. Slaughter and justice cannot dwell together.
Isaac Bashevis Singer
To apply a term such as "innocence" to an animal is foolish anthromorphising. An animal is neither innocent nor guilty. It is simply an animal.
It is just like man's vanity and impertinence to call an animal dumb because it is dumb to his dull perceptions.
Mark Twain
And to pretend to see something that isn't there is at best self-deception.
Kindness and compassion towards all living beings is a mark of a civilized society. �Racism, economic deprival, dog fighting and cock fighting, bullfighting and rodeos are all cut from the same defective fabric: violence. Only when we have become nonviolent towards all life will we have learned to live well ourselves.
Cesar Chavez
(Who used to gather up his fellow workers to beat the crap out of illegal grape pickers.) These things might better be described as cruel violence. Violence itself is can be good or bad, depending on the circumstances.
There is no fundamental difference between man and the higher animals in their mental faculties... The lower animals, like man, manifestly feel pleasure and pain, happiness, and misery.
-- Charles Darwin (1809-1882)
Yeah, animals demonstrate such a highly "evolved" capacity for moral reasoning.
"If a man aspires towards a righteous life, his first act of abstinence is from injury to animals."
-- Albert Einstein
"Righteousness" is a religious standard, so its requirements are set by God, not man. To the best of my knowledge, Einstein was neither a god, nor a Vegatarian (or Rastafarian, for that matter!) As such, he survived through the injury of animals, albiet at the hands of others. Therefore I'm guessing that what he was saying was that a man who wishes to be good should refrain from cruelty to animals.
I'm off to bed now !!!
This is a wonderful collection of some of the most ridiculous statements regarding animals and humans ever uttered. 
