People tend to care about dogs because they generally have more experience with dogs as companions; but other animals are as capable of suffering as dogs are. Few people feel sympathy for rats. Yet rats are intelligent animals, and there can be no doubt that rats are capable of suffering and do suffer from countless painful experiments performed on them. If the army were to stop experiments on dogs and switch to rats instead, we should not be any less concerned.

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.

Knowing that we can control our own behaviour makes it more likely that we will.

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.

Animal factories are one more sign of the extent to which our technological capacities have advanced faster than our ethics.

Of course, infanticide needs to be strictly legally controlled and rare - but it should not be ruled out, any more than abortion.

The animal liberation movement is saying that where animals and humans have similar interests - we might take the interest in avoiding physical pain as an example, for it is an interest that humans clearly share with other animals - those interests are to be counted equally, with no automatic discount just because one of the beings is not human.