If it is in our power to prevent something bad from happening, without thereby sacrificing anything of comparable moral importance, we ought, morally, to do it.

Sci-fi is often a metaphor. I think it's more the themes and questions that science fiction raises rather than the exact predictions that should guide us.

To give preference to the life of a being simply because that being is a member of our species would put us in the same position as racists who give preference to those who are members of their race.

What you could say, and what I do argue in the book, is that he doesn't have as much concern for the lives of Iraqis as he does for the lives of Americans, or even frozen American embryos.

All the particular moral judgments we intuitively make are likely to derive from discarded religious systems, from warped views of sex and bodily functions, or from customs necessary for the survival of the group in social and economic circumstances that now lie in the distant past.

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.

If we are prepared to take the life of another being merely in order to satisfy our taste for a particular type of food, then that being is no more than a means to our end.