I am using ['Ethics'] to cover an enquiry for which, at all events, there is no other word: the general enquiry into what is good.1And he did mean it when he said 'general.' Though we often speak of 'moral good' and 'non-moral good,' Moore's view of ethics encompassed both. His problem — in my view — was failing to notice that 'good' is a term with a variable missing; all that is good is good for an end.2 When we distinguish between moral and non-moral good, we are distinguishing between moral and non-moral ends.
For example, we might say it's good to check more than Wikipedia because we aren't confident in reaching the epistemic end of having true beliefs by checking Wikipedia alone. Or we might say that it's good to avoid saturated fats. Why? Because the end of remaining healthy is endangered by consuming saturated fats in high quantity.
What end is at stake when we claim things are morally good? I don't have the answer today, but I do have two suggestions:
First, because of the end-facilitating relationship between 'good' things and the sense in which they are good, we should be able to survey the things we are most certain are morally good or bad and try drawing an inference to the best explanation, i.e. which end most plausibly generates these 'good' and 'bad' judgments? Yes, this is an empirical approach to defining moral goodness.
Second, we shouldn't assume all moral judgments are based on one, fundamental end. There's good reason to think our judgments are drawn from multiple ends,3 and that moral goodness is a complex — perhaps even incoherent — concept for this very reason.
1. From http://fair-use.org/g-e-moore/principia-ethica/chapter-i
3. See http://faculty.virginia.edu/haidtlab/mft/index.php