[Serious] Generally speaking, is philosophy a worthwhile subject of study?

[polymath257]

That's an interesting idea.  That other alien species would have to be absolutely incapable of understanding human beings in that they couldn't logically deduce the same ethical positions as humanity, regardless of whether or not it agreed with them.

You really don't need aliens for this thought exercise, though.  People from different cultures satisfy the setup and..fwiw, we have a somewhat spotty track record in that regard - not necessarily in understanding, but in agreement, at least.  

This is something that philosophers and social scientists are actively researching.  As I mentioned before, it turns out that our ethical statements can be mapped and predicted.  If the aliens (or any other people) can do math, they can figure out our ethics.  I'd also like to point out that you've casually dropped a pregnant assumption about there being no universal ethics.  We think that's untrue, obviously by reference to our very different groups since we have no aliens to refer to - but also by looking at proto-ethics in non human species.  Any living creature is going to have at least some of the same interests and concerns.  Hominid or cephalopod.  Earth or Planet Blip.  Biologicial relativism is, itself, something we understand, and it's not beyond the pale to think that some other creature similarly possessed of the ability to think about these things might understand the same.  Biological relativism is, itself, a suggestion that a certain range of ethics are universal across living creatures.

Mind you, you may be right, but you might want to tighten up the delivery, as it stands you've suggested directly contradictory things to explain why you think what you do.  If biological relativism is true, then ethics is not limited to our species or our biology.  It certainly doesn't seem to be limited to us even between the species on this planet.  So that's a rough spot.  Incoherent, and counterfactual.

It isn't necessarily that they wouldn't be able to understand *why* we have the ethics we do. it may just be that they consider our ethics to be incompatible with theirs. Which assumptions would they deduce our ethics from?

Biological relativism is part of the point. Why would we expect to have universal answers to ethical questions? Is killing innocent children always unethical, no matter the biology? I am skeptical.

I'm curious what you consider to be the interests and concerns that would be universal. Self-preservation might not be universal in species with high degrees of common genetics (like bees). It may well be that killing an otherwise healthy and 'ethical' member of a society would be justified in some species.

I'm not saying that *ethics* is limited to our species. But the basic ethical principles may well be limited to species similar to us. I'm not surprised when other primates have proto-ethics similar to ours. I would be less sure about insects, for example.