Singer and Mason make a few points near the end of their book I would like to call into view. To begin with they mention Pollan and a few other authors and their idea behind a happy life equaling okay. Singer and Mason offer a weak rebuttal to the argument that "eating meat from farms that give pigs good lives cannot be bad for pigs, since if no one at meat, these pigs wouldn't exist". The only counter they have is that Pollan feels a level of discomfort coming to this conclusion. They say that since this is 'essentially' a utilitarian view it is bad because utilitarians can also justify killing retarded orphans. How the fact that utilitarians can also justify killing retarded orphans makes this other 'essentially' utilitarian view bad is a bit foggy. Perhaps using a word other than 'essentially' and making the connection here would further strengthen their argument.

Another issue I have is in regards to the conclusion on killing creatures without the potential to become as intelligent/rational/etc. as humans. If someone believes this is okay, that a retarded human incapable of developing like other humans do is allowed to be killed, Singer and Mason seem to have no real response. They talk about how this is not an impregnable defense, but it is still a defense they do not completely bring down. When Scruton talks about human beings being fulfilled by their aspirations and achievements he lacks another point that would help refute Singer and Mason's response that Scruton must support killed retarded people. Human beings are also fulfilled based on relations, even with retarded people, where as animals are not. Their offspring will even be eaten/abandoned if found to be retarded. Humans on the other hand will have emotional damage due to attachments we can forms with them, which as we all know can lead to physical damage (emotional to physical that is).

In the end I'm a little fuzzy on all this myself, and I've mostly raised more questions than answered any.