The words "subjective" and "objective" cause lots of confusion. In a way, their misuse is responsible for the confusion about subjectivism in ethics (the view that moral judgements are nothing but statements or expressions of personal opinion or feeling and thus that moral judgements cannot be supported or refuted by reason).

The ordinary non-philosophical (i.e., oversimplified) view is that the word "subjective" is the complete opposite of the word "objective." If something is subjective, it's not objective; if something is objective, it's not subjective. "Subjective" is supposed to mean "from someone’s point of view." "Objective" means "not just from someone’s point of view." An objective matter is one that everyone (who is sane, rational, and appropriately informed) will agree about. "Subjectivity" connotes lack of objectivity. Ethical "subjectivism" is the view that since we can’t be "objective" about morality, morality must be purely "subjective."

Furthermore, on the ordinary non-philosophical view, "subjective" goes with words like "belief" or "opinion." The idea is that subjective matters are not certain. "Objective," on the other hand, means "certain" or "factual." "Objective" matters are those that can be measured or quantified. For example, the answers to questions such as "How many desks are in this room?" and "What is the current temperature in this room?" would be objective. Note that these questions have precise mathematical answers, and anyone with access to the appropriate properly-working measuring devices would agree what those answers are.

To summarize, on the ordinary (oversimplified) view:

"Objective" = public stuff: publicly-observable events, knowledge, facts

This way of making the distinction leads to philosophical trouble.

Consider your experience of a headache versus your experience of the Eiffel Tower. Naturally, you have your own personal private "subjective" experience of the headache, and nobody else can have your headache for you. So each person's headache is subjective. Now of course you could apply this very same reasoning to your experience of the Eiffel Tower. There you are in Paris, looking at the Eiffel Tower, and you think, "Gee, no one else is having this precise experience of the Eiffel Tower, so this experience of mine is just as subjective as my headache!" And that wouldn't be wrong, of course, in a way; it's true that no one else has your precise experience of the Eiffel Tower either.

The really fun philosophical problems begin when people use the ordinary subjective-objective distinction in combination with another presupposition: that everything has to be EITHER subjective OR objective. For example, suppose you have a headache. You feel it, and nobody else does, so it’s subjective. But look what other notions go with "subjective": if it’s subjective, it’s just your opinion! (Some people even say that because the headache does not exist as a physical object, like the Eiffel Tower, it doesn’t exist at all! It’s really all in your mind. This is the philosophy behind Christian Science.) But this seems wrong. Your pain is indubitably real and perfectly objective for you, in the sense that it's not just your opinion. Note your pain seems also to be objective for your doctor, e.g., when she says "You’ll feel a little discomfort" or "I’ll give you some Demerol for that pain." Your doctor does not ignore or belittle your pain (I hope!).

A reverse example: suppose you see the Eiffel Tower. Well, all you really know is that you had a subjective experience of seeing the Eiffel Tower. And that’s all anyone ever has, so why say the Eiffel Tower — or anything — exists objectively? But we do (at least most of us do). We think emotions and pains are real AND we also think physical things are real. And yet insofar as we persist in associating "subjectivity" with all experience (experience of pains and feelings AND experience of physical things), we can't then be certain anything exists "objectively," independently of our experiences. All we know are our experiences, which are "subjective," and thus just our opinion. We've been led down the philosophical road to skepticism and perhaps even metaphysical idealism. And once you make these two moves (1- accept the oversimplified subjective-objective distinction; and 2- presuppose that everything has to be either subjective or objective) there's no way out! You lose the notion of objectivity altogether.

But when you live your life, you do seem persistently to believe and act as though there is a world independent of your mind — a world you didn't make up and that you don't control. In other words, the ordinary oversimplified subjective-objective distinction leads you to a philosophical position that is completely at odds with your ordinary beliefs and practices. Philosophy is supposed to clarify, enlighten, explain, etc.; all this view does is confuse and mystify! Contemporary philosophers conclude that something is very wrong with the ordinary opposition of "subjective" and "objective."

Subjectivism in ethics is really just another example of the same kind of puzzle. The subjectivist says that because people have subjective feelings about ethical matters, that claims about ethical matters themselves must be subjective and therefore merely matters of opinion, and therefore not liable to adjudication by reason or other objective methods.

Philosophers used to be stuck on this problem but most are no longer puzzled! Here’s the way to solve the problem.

We must distinguish two kinds of subjectivity:

Something is metaphysically subjective if its mode of being is private. Many real things are like this. Emotions and pains are metaphysically subjective, in that they exist only as they are experienced. They are no less real on that account, however.

A claim is epistemologically subjective if there are no generally recognized methods for deciding whether the claim is true or false. Epistemologically subjective claims are mere matters of opinion: e.g., "Chocolate ice cream tastes better than vanilla."

Now make similar distinctions for objectivity:

Something is metaphysically objective if its mode of being is public. So the Eiffel Tower exists in a metaphysically objective way, since its existence does not depend on its being experienced.

Finally, a claim is epistemologically objective if there are generally recognized methods for deciding whether the claim is true or false. For example, the claim "There are 45 desks in this room" is epistemologically objective. Note that "objective" now does not mean the same as "true," since the claim "There are 45 desks in this room" is objective whether or not it is true or false. "Objectivity," properly understood, refers to availability of a method for deciding truth and falsity.

Now here’s the payoff. If an event is metaphysically subjective, claims about it can still be epistemologically objective! For example, consider pain again. If you had severe and unexplained pain, you would probably go to a doctor who would treat the pain as well as the underlying physical cause. There are even doctors who specialize in relief of pain. There are well-recognized physical drugs and therapies for pain relief. In other words, there’s all kinds of epistemologically objective knowledge about what is metaphysically a subjective occurrence.

Do you see how this helps us out of ethical subjectivism? Look again at Hume’s argument. Doesn’t Hume’s first premise exemplify exactly the mistake we’ve been talking about? Hume says in effect that moral judgments are either subjective or objective in the following ordinary senses of "subjective" and "objective":

"Subjective" = private stuff: beliefs, feelings, emotions, opinions, etc.

"Objective" = public stuff: publicly-observable events, knowledge, facts

Hume then presupposes that if a moral judgment is subjective, it can’t be objective (otherwise the disjunctive syllogism wouldn’t work). If you feel it, you can’t be objective, since feelings are subjective. If you can’t be objective, you can’t use math or logic, i.e., you can’t reason.

Pain is felt, but it is more than "just feelings": there’s a lot more we can say about pain than "I feel it" or "ouch!" In the same way, morality is more than "just feelings" and there’s a lot more we can say about it than "I feel it" or "Yuck!" or "Yay!" What we’ve just shown is that although moral feelings exist in a metaphysically subjective way, there can still be epistemological objectivity about them. Just as doctors can use epistemologically objective scientific methods to investigate metaphysically subjective matters like pain, so we can use epistemologically objective rational methods to investigate metaphysically subjective matters like moral feelings.

The basic problem with ethical subjectivism, in other words, is not its observation that people have feelings about moral matters. People do have feelings about moral matters; no question about that. But the fact that people have feelings about morality doesn’t disqualify them from thinking about it too. And once you allow that people can reason about morality, you undermine ethical subjectivism entirely, since as a matter of fact, not all arguments are equivalent, some are better than others, and so some people’s moral claims are objectively more worthy of belief than others — because they are more reasonable.