There could conceivably be circumstances in which an experiment on an animal stands to reduce suffering so much that it would be permissible to carry it out even if it involved harm to the animal... [even if] the animal were a human being.

The prescription of the equality of human beings is not a description of an alleged actual equality among humans: it is a prescription of how we should treat human beings.

Those who purchase meat, fur, and leather have no right to be shielded from the sights and sounds of the slaughterhouses from which these products were produced.

I can tell you that too much money is corrupting American politics. Don't blame the American public. The U.S. Supreme Court has a lot to answer for, because it has made it impossible for Congress to reduce the corrupting influence of money on American political life.

It's also much clearer how much damage the occupation of Iraq is doing to America's reputation and prestige around the world; and that's just starting now to hit home in the United States.

Human decision-making is complex. On our own, our tendency to yield to short-term temptations, and even to addictions, may be too strong for our rational, long-term planning.

Were we incapable of empathy – of putting ourselves in the position of others and seeing that their suffering is like our own – then ethical reasoning would lead nowhere. If emotion without reason is blind, then reason without emotion is impotent.