We wait until Pandora's box is opened before we say, "Wow, maybe we should understand what's in that box." This is the story of humans on every problem.

One thing is certain: you will find plenty of worthwhile things to do. You will not be bored, or lack fulfillment in your life. Most important of all, you will know that you have not lived and died for nothing, because you will have become part of the great tradition of those who have responded to the amount of pain and suffering in the universe by trying to make the world a better place.

What one generation finds ridiculous, the next accepts; and the third shudders when it looks back on what the first did.

It is a mistake to assume that the law should always enforce morality.

My aim is to advocate that we make this mental switch in respect of our attitudes and practices towards a very large group of beings: members of species other than our own - or, as we popularly though misleadingly call them, animals. In other words, I am urging that we extend to other species the basic principle of equality that most of us recognize should be extended to all members of our own species.

In appropriate circumstances we are justified in using humans to achieve goals (or the goal of assisting animals).

Once we ask why it should be that all human beings - including infants, the intellectually disabled, criminal psychopaths, Hitler, Stalin, and the rest - have some kind of dignity or worth that no elephant, pig, or chimpanzee can ever achieve, we see that this question is as difficult to answer as our original request for some relevant fact that justifies the inequality of humans and other animals.