Most all ethical theories have a problem with them, whether it has some sort of internal inconsistency, has no answer for a certain scenario, or whatever. How can anyone accept an ethical theory that they know is flawed? Don't the flaws mean we need to keep looking and thinking?

There are two sorts of things that might be at issue here and they call for different answers.

If I want the best ethical theory we can come up with, and the available alternatives all seem flawed, then that's a reason to keep looking and thinking—especially if the goal is to get as close as possible to the (probably unattainable) ideal theory.

But if "accept an ethical theory" means something like "use it as the basis for making ethical judgments," then the issue changes. That's because it's debatable, to say the least, that the best way to make ethical judgments is to come up with an ethical theory and apply it.

What's the alternative?

Here's one. Assume that by and large, we're able to make reasonable ethical judgments. The job of an ethical theory on this view is to provide a coherent account of what makes those judgments right or wrong (or true or false, or whatever the appropriate contrast may be.) It could very well be that even though we have the capacity to make sound moral judgments, boiling the judgments down to a tidy theory is very difficult. If that's so, then we'd expect that our ethical theories would be inadequate in various ways. But that wouldn't give us a reason to become ethical skeptics. On this way of looking at things, ordinary ethical knowledge is a bit like practical knowledge or practical skills: we don't need to know the theory to get things right. Theoretical thinking might feed back into our practical skills and refine them, but it's not the place to start.

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