In 1992, I read an essay that changed my life: “Moral Objectivism,” by the Wunderkind philosopher Michael Huemer. Even as an undergraduate, Huemer had a gift for making the hardest questions simple:

[S]ubjectivism must say (1) that moral judgements are not judgements at all and do not have propositional contents (that is, don’t represent genuine claims) or, if they do, (2) what they claim is always false, or, if it is true, (3) it represents something about the subject making the statement rather than the object the statement purports to be about…

But each of these three views is surely false. The first has been refuted above in section 4.2, in which I presented four arguments to the effect that a moral statement is a proposition. The second runs contrary to patent observations that virtually everyone can see, such as the preferability of happiness to misery, the impermissibility of murder, etc. And the third view… can always be refuted by simple thought experiments, the general point of which is to hold the nature of the object constant and vary assumptions about the nature of the subject, and notice that the moral qualities remain unchanged. For instance, supposing that we all liked Nazism, yet all the same, it wouldn’t make Nazism right…

Fourteen years later, Huemer is a philosophy professor at the University of Colorado, and has turned his early insight into a brilliant but accessible book, Ethical Intuitionism. If you read one book on ethical philosophy during your lifetime, this should be it!