Overall, this book is a powerful argument in favor of animal rights and animal welfare. I would unhesitatingly recommend it to friends, meat-eaters, the general public, etc. The Rawslian veil of ignorance, which Rawls termed the "original position" (already a powerful idea), is refined by Rowlands into the "impartial position," and it works marvelously. In a nutshell, it amounts to imagining that you are creating a society, but that you do not even know what species of animal you will end up being in that society. What choices would you then make as to the make-up of that society? However, while the first half of the book is excellent, it begins to falter in the second half.
Here are the main problems I see with the book:
In the chapter titled "Killing Animals," Rowlands argues that it would be morally correct to save a baby over an 80-year-old in a lifeboat scenario and to save a dog over a human who has 15 minutes to live. I agree with the latter, but the former I'm not so sure about. In the discussion, Rowlands seems to forget (or at least de-emphasize) that a baby has a future in only the weak sense, and he conveniently sort of brushes this fact under the rug. Nor does he tackle the more difficult issue of whether to save a baby or, say, a 20-year-old. Basically, it seems like he's at a loss to say just when the potential value a life may acquire in the future, as potentially acquired by a being currently only having a future in the weak sense, overrides the interests of a person who already possesses a future in the strong sense.
Second, his discussion of animals in experiments is lifted, virtually example for example, out of Singer's Animal Liberation. It's interesting to note that, in this chapter, he even concedes that there may be some animal experiments that were absolutely necessary to medical advancements that benefited the vital interests of humans. But, he goes on, the end does not justify the means--which is a strange thing to say because 1.) He’s a self-identifying consequentialist and 2.) He states in the chapter "Animal Rights Activism" (in a general vein unrelated to specifically animal rights issues) that it's widely accepted, and he agrees, that violence can be justified if it serves the greater good. So there's a pretty big inconsistency here.
Third, his brief discussion on zoos talks about what animals lose from being kept in zoos, and what humans potentially gain by keeping animals in zoos, but it does not mention anything at all about what animals may gain by being kept in zoos. He also doesn't make a distinction between the moral acceptability of keeping certain animals in zoos versus certain other sorts of animals based on their differing behavioral tendencies and differing needs. Furthermore, his entire discussion presupposes that all animals necessarily value autonomy in the exact same sense that humans value autonomy.
Finally, to take an example from his discussion on hunting: He states, correctly, that the deer population in many areas of the United States is only out of control because we have exterminated many of their natural predators (wolves). He implies that the deer population should be kept under control by re-introducing the wolf. Therefore, he says, arguments that say that hunting is morally valid because it keeps the deer population under control are completely wrong, because the only reason why hunting is necessary is because we killed off a lot of the wolves. Yes okay, but this is an oddly idealistic position. The more interesting, and difficult, question is: Assuming people won't re-introduce the wolf, can hunting be justified in our current context, at all?
Now, none of these criticisms are to imply that Rowlands is necessarily wrong about anything he's said, but I only want to point out some of the shortcomings that, to me, seem very relevant to the discussion and appear to be neglected solely due to their greater difficulty.