it seems clear to me that people are able to form relationships with dogs, cats, rats, and several other types of mammals (this is consistent with the notion that more-similar animals are able to form relationships with each other, on a sliding scale).
People are also able to form relationships of this kind with, say, ELIZA or virtual pets in video games or waifus. This is an argument in favor of morally valuing animals, but I think it’s a weak one without more detail about the nature of these relationships and how closely they approximate full human relationships.
Do you care about potential posthumans who share all values you currently have, but have new values you don’t care about one way or another, are vastly more intelligent/empathetic/able-to-form-complex-relationships that you can’t understand? Do you expect those humans to care about you?
Depends. If they can understand me well enough to have a relationship with me analogous to the relationship an adult human might have with a small child, then sure.
To the extent that you are not able to form relationships with other humans (because they are stupider than you, because they are less empathetic, or just because they’re jerks, or don’t share enough interests with you), do you consider them to have less moral worth? If not, why not?
I hid a lot of complexity in “in principle.” This objection also applies to humans who are in comas, for example, but a person being in a coma or not sharing my interests is a contingent fact, and I don’t think contingent facts should affect what beings have moral worth. I can imagine possible worlds reasonably close to the actual one in which a person isn’t in a coma or does share my interests, but I can’t imagine possible worlds reasonably close to the actual one in which a fish is complicated enough for me to have a meaningful relationship with.
I had fish once, but no complicated pets.
People are also able to form relationships of this kind with, say, ELIZA or virtual pets in video games or waifus. This is an argument in favor of morally valuing animals, but I think it’s a weak one without more detail about the nature of these relationships and how closely they approximate full human relationships.
Depends. If they can understand me well enough to have a relationship with me analogous to the relationship an adult human might have with a small child, then sure.
I hid a lot of complexity in “in principle.” This objection also applies to humans who are in comas, for example, but a person being in a coma or not sharing my interests is a contingent fact, and I don’t think contingent facts should affect what beings have moral worth. I can imagine possible worlds reasonably close to the actual one in which a person isn’t in a coma or does share my interests, but I can’t imagine possible worlds reasonably close to the actual one in which a fish is complicated enough for me to have a meaningful relationship with.