Is there a reason why one cannot hold multiple ethical non-cognitivist positions? Can one be both an emotivist and a prescriptivist, for example? — HamiltonB

What is a non-cognitivist position? What an emotivist or a prescriptivist?

Seems to me you can "hold" all the positions you want, but probably only one at a time.

Wouldn't that depend on whether you are seeking a logic based objective prescriptive ethics or a pragmatic de facto psychological or social explanation?

Can you rephrase that? I'm not sure what you mean.

I don't see why. If there's no moral thing-in-itself than the number of positions you have on it are merely descriptions of a non-thing anyway.

I'll put it this way, if you're claiming there is a "thing" there, then your position toward it ought to be accurate. But non-cognitivism claims there is no "thing" to morality, so what matters it?

Non-Cognitivism is a group of meta-ethical positions that claim moral language is not truth-apt (meaning it cannot be true and cannot be false) and that when people make moral claims, they are not actually asserting propositions.
An ethical cognitivist would understand "killing is wrong" to mean "killing has the property of wrongness". But a non-cognitivist would claim killing has no moral properties and that moral language like "killing is wrong" does not actually describe or refer to anything in the world.

Emotivism and Prescriptivism both fall under the Non-Cognitivist category.

Emotivism is the view that what people are doing when they moralize is expressing their emotions or attitude. So from the Emotivist perspective, a moral claim like "killing is wrong" is interpreted as "boo killing!".

The Prescriptivist would say that when people moralize, they are are making commands. So "killing is wrong" actually means "don't kill!".

You're right, non-cognitivists say there is no moral thing, meaning there are no moral facts or properties. But what the non-cognitivist is trying to do is explain what people are doing when they use moral language. If, when people moralize, they are not actually referring to some moral fact, then what are they actually doing? So the non-cog is not trying to account for the "non-thing" of morality but trying to account for moral language.

Interesting. Well, I know emotivism because I once held that view. I don't know prescriptivism. If I did, that might shed some light on the answer. But I don't, so I don't know.

Sorry.

Way more interesting and thank you (I understand and appreciate the effort you just went to)! Chopping from both sides the same tree, let's see if we can get this thing down reasonably quickly. I think one "chop" is to inquire closely into the notion of "truth-aptness."

What is true, I aver, is always with respect to some criteria. But with respect to that criteria it is truth-apt. Criteria can be deconstructed to a meaningless granularity - but in that case the criterium as criterium has been destroyed. Further, some care is needed with the words. That "killing is wrong" may be true under particular criteria, but the general sense of things is that the proposition that killing is wrong is itself just plain wrong. The more useful and accurate expression being that some killing is wrong - the which being a whole other topic.

With all these, then, usage is critical and failure of appropriately accurate usage is fatal to understanding. So far so good?

I believe you can. I have interacted with some people who held an error theory about descriptive properties, but accepted non-cognitivsm about normative statements (what we ought to do)

I'm not sure what you're getting at actually. Could you rephrase it?

I understand truth-apt to mean "capable of being true or false".
Descriptive sentences/statements are truth-apt because the statement either describes something accurately or it describes something inaccurately.

Questions, commands, and expressive sentences are not truth-apt because these types of sentences are not propositions, not making claims about reality.
Emotivists think moral utterances are expressive.
Prescriptivists think moral utterances are commands.

My comment is more to the precondition of the non-cognitivist's determinations. What, that is to say, is their concern? And usually careful use of language makes most concerns evaporate.

If a non-cognitivist, for example, cavils at proscribing killing, we can ask what, exactly, his problem is. And without belaboring the example, it sees pretty clear to me he has either a mental health problem - he wants to kill or be killed, or have permission for ether - or a problem with language, and a problem with language that likely has little to do with the content.