How should humans treat animals?

In 1974, philosopher Thomas Nagel argued it is impossible to know what it is like to be a bat. We can know, however, to any degree desirable, how a bat lives its life and, if we wish, treat it accordingly.

Treating animals with regard to what they are does not mean forgoing interactions with them altogether. Most welfare issues arise from the mistreatment of domestic animals. The evolutionary process of domestication led to many stable and mutually beneficial relationships between animals and humans. Most modern welfare issues arise from humans having recently broken their part of the domestication "contract" in the name of mass production. Up until about two hundred and fifty years ago that contract worked well, and it still does in some cases, such as truly free-range chickens and domestic dogs and cats.

Treating animals with regard to what they are also solves the problem of non-sentient versus sentient animals and degrees of sentience. Because non-sentient animals feel no pain, they are of little interest to the animal welfare philosophers. Treating animals on the basis of what they are as evolved beings makes the question of their degree of sentience irrelevant. Further, in contrast to the animal welfare approach, it extends the halo of concern far beyond sentient animals, because even animals that feel no pain can be treated on the basis of what they are as evolved beings. Is this not, in fact, simply what most humans want for themselves?

If we judged the treatment of animals on the basis of what they are as evolved organisms instead of what we imagine their feelings to be, we still might not agree on how to treat them. But we would put the debate within ourselves and within our culture on a more objective basis. It is regrettable the animal welfare movement has cast, perhaps irrevocably, the issue of how to treat animals in such a human-centric perspective.