Atheism and Ethics

[Disagreeable]

So I guess there can be moral facts if we define morality as being about wrongness and wrongness as being about harm.

Right.

But it seems tautological and just an arbitrary definition.

I have no problem with it being tautological because that just means it's true by definition.

I don't agree that it's an arbitrary definition, though. I think it's a definition that makes sense of moral language. When people talk about 'right' and 'wrong' . . . harm seems to be the topic.

Why should I care about harm (I do, but by what standard should I).

Well under my system of morality being about harm, to say you should do something just means that doing it decreases harm. So the question you are asking is "Does caring about harm decrease harm?". The correct answer is probably "sometimes". But it's a practical ethics question, rather than a metaethical question.

Perhaps that is not a mind independent (non-institutional) categorical imperative, and if so fine I get on board with it and fail as much as the next man and succeed hopefully at least as well.

Well good!

But to be moral realist to me is to say that this isn’t just a matter of definition, it is a matter of a property (of the universe?) that exists, that our actions can live up to or fall short from.

And the property of harm exists. We just have to start with definitions. We always have to start with definitions.

We don’t think that there are objective standards about tickling (apart from the way my brother bullied me with it as a child and might explain a lot), so why think there are standards about harm

Because there are moral facts about what is most and least harmful. There are also facts about what tickles us. But the difference is that tickling is not a plausible definition of wrongness. But harm is. It's about making sense of moral language. That's what metaethics is about!