Animal Rights Once More
Alon Levy responds to my earlier post in which I claimed that liberals reject the ecological fallacy in the case of same-sex marriage and gender discrimination in jobs, but not in the case of animal rights. His first line of attack -- denying the second premise of the first argument -- is a bit beside the point, since my post was about the internal logic of the arguments. And in any event, I would deny the second premise of the animal rights argument (only things which have "reason" have rights).
Levy's second line of attack is pragmatic. He says that one the one hand it's possible to directly measure fertility or upper-body strength, but that "reason" is too vague to measure directly, so we need to use the crude proxy of defining reason as a property of humans. On the other hand, he says that despite our inability to clearly define it, the overlap in "reason" between humans and animals is small enough that we can be categorical about it. While I disagree with Levy's assessment of how small the overlap is, it's true that the ecological fallacy is less of a fallacy the more significant the difference between the groups is -- or in other words, a strong first premise can rescue an otherwise fallacious argument, since an argument beginning "all and only" rather than "most" would be sound. (I would note as well that the first premise of the marriage argument is also quite strong.)
However, just showing that there's a difference in the degree of "reason" between humans and animals isn't enough to make the first premise strong. One also has to show that that gap occurs at the morally relevant point. After all, the degree of harm done by speeding is far less than that done by murder, but that doesn't mean that speeding isn't still a crime. (I would base rights on interests rather than ability to reason, in which case it's clearer that, while humans generally have much more complex and important interests, animal interests are not therefore non-entities.)
Levy wraps up his post with a version of the argument I criticized in my follow-up post -- according a vaguely-defined lesser moral status to animals. He says that human interests should always trump those of animals, but that ceteris paribus we should protect the well-being of animals. Taken strictly, this claim effectively does nothing for animals, since anything we do to protect their well-being will decrease human well-being in some amount. Just administering anaesthetic to a lab monkey, for example, costs money and researchers' time (as well as the time and patience of those who have to listen to them moan about how PETA makes their lives so hard). To avoid triviality, animals' interests would have to be able to trump humans' -- either by establishing a certain level of human interest that can be overruled, or an exchange rate favorable to humans. (This could be perhaps done within a pluralist system in which some interests are protected by absolute rights. In this case human rights would trump human non-right-interests and the rights (if they exist) and non-right-interests of animals, animal rights (if they exist) would trump the non-right-interests of both humans and animals, and when only non-rights-interests are at issue we use an exchange rate favorable, but not overwhelmingly so, to humans.)