In an earlier post I argued that the categorical imperative entails that we are not allowed to use sentient beings as a means only. The semantic Terrorist challenged me on this (and other things) and argued that I couldn’t really mean it. But I did, and I still do. But what does it mean to not treat something as a means only?
Let’s start with the human case. Does the categorical imperative entail that I cannot ride the bus? Afterall, don’t I use the bus driver as a means when I ride it to work or the club or whatever? Not necessarily. I certainly treat him as a means, but I needn’t treat him as a means only. So, what the categorical imperative entails is that I recognize that he is an individual. This requires no more than a friendly smile, or greeting, and perhaps a ‘thank you’ upon exiting. What this will actually mean in detail will depend on the actual relationships that one has to these individuals. So, one has a duty to treat ones wife as an end in itself, and so too with the bank teller. But what it will actually end up meaning is quite different because of the relationship that one has. So there will be ways that you could treat the bank teller that might count as respecting his being an end in himself, but those same actions would not count as treating your wife as an end in herself, and vice versa.
It seems to me that this general idea can be extended to animals. We have a duty not to treat them as means only, which clearly rules out the way that we treat them now. But we can treats them as means, but we are obligated to do so in a way that respects their sentient capacities. So, we are not morally required not to use the donkey or horse as a pack animal but we are obligated to recognize that the animal deserves to be treated with respect and in a way that does not cause it unecessary harm or suffering. It also seems that what ones duties are depends on the relation one has to the animal. So, one may be obligated to treat ones pet in ways that do not come up with respect to wild animals (that is, beyond the basics due to all sentient beings).