Is there such a thing as moral truth?


Of all philosophical positions on moral truth, moral realism is probably the most intuitive. It starts by answering two different questions with “yes”: Can moral claims, i.e. propositions employing moral concepts, be true? And if so, are at least some moral claims actually true?

But that is not all it says—moral realism is very specific as to “why propositions employing moral concepts may have truth values”1. Its answer to that question is also the reason why it is so intuitive: it naturally extends our intuitive realist semantics from the factual to the moral domain. Intuitively, the claim that the cat is on the mat is made true by the fact that the cat indeed is on the mat. This fact and the entities referred to by “cat” and “mat” are independent of us and our concepts of cats and mats. In the same way, moral realism contends, the claim that we have an obligation to treat animals well is made true by the fact that we indeed have an obligation to treat animals well. This fact and the normative entity referred to by “obligation” are independent of us and our concept of an obligation.

Thus, according to moral realism, “propositions employing moral concepts may have truth values because moral concepts describe or refer to normative entities or facts that exist independently of those concepts themselves.”2 In other words, moral realism holds that “moral claims do purport to report facts and are true if they get the facts right.”3

Apart from its intuitive appeal, moral realism – if correct – may offer another huge advantage: It seems to provide a formidable argument against moral skepticism, i.e. the view that “nobody is ever justified in holding any substantive moral belief”4 or making a moral claim, let alone knows that it is true. If someone challenges us why we are justified in making such a claim or how it can be true, as moral realists we can easily answer: because it describes a fact. According to moral realism, there is no fundamental difference between empirical and moral claims, no special dubiousness about moral as opposed to empirical truths: in both cases, claims are true if they get the facts right.

But that, of course, opens up a lot of other questions: How are we supposed to find out if a moral claim is true – if what it purports to report is indeed the case? Most of the time, we know how to check empirical facts, e.g. verify whether the cat actually is on the mat. But how are we to check moral facts, e.g. verify whether we actually have an obligation to treat animals well? When checking for cats on mats, we might rely on our visual perception – but do we also have a moral perception, a moral sense we somehow grasp moral facts with?5

And if that was the case, what exactly would we grasp with it? What kind of thing is a moral fact or a normative entity? In which part of the world do they reside? Are they part of the natural order – and if so, how can their normativity transcend mere utility or convention? If not, doesn’t that mean we have to give up even the most basic philosophical naturalism?6

As these questions show, moral realism either collapses into a weak naturalist understanding of normativity or depends on strong, probably non-naturalist epistemological and metaphysical assumptions. This dilemma is especially problematic for arguing against the moral skeptic. For, on the one hand, a naturalist understanding of normativity as based on utility or convention is of limited use against moral skepticism: It doesn’t provide an argument for the truth or truth-aptness of “categorical or absolute moral beliefs“, even if it allows for “weaker kinds of moral beliefs”7 to be true. On the other hand, strong epistemological and metaphysical assumptions make moral realism even less useful against the moral skeptic, especially if she is a naturalist: Why should she overturn her metaphysically modest position in favour of metaphysically much more ambitious and thus—in her view—dubious speculations?8 Therefore, in both versions, moral realism is a blunt knife against moral skepticism.

But if we reject both naturalist and non-naturalist moral realism, aren’t we then left without moral truth? Not necessarily. What I called our intuitive realist semantics is based on a “representationalist assumption”: the view that “linguistic items … ‘stand for’ or ‘represent’ something nonlinguistic9 – in other words, “that it is the function of all of our concepts … to describe reality”10. This is why the moral realist needs non-linguistic normative entities as parts of reality: They are what moral concepts represent. But this paradigm is not without alternatives: Instead of taking the alleged representational function of linguistic items as the foundation of meaning, we can start with their use. This account of language, which goes back to Wittgenstein and Dewey, can then be spelled out for moral concepts and claims in different ways:

We can either take moral claims and construe them as “moves in a linguistic game of ‘giving and asking for reasons’”11. On this inferentialist account, the meaning of moral claims and, derivatively, concepts, consists in their position in our web of reasons. It follows naturally that we are justified in making a moral claim if we have the reasons to back it up. Habermas’s discourse ethics and its criteria of moral justification, e.g., can be read as a pragmatist moral theory along these lines.

Or we can understand moral concepts as “the names of the solutions of problems”12. On this constructivist account, practical philosophy works out solutions to practical problems by “constructing an account of the problem reflected in the concept that will point the way to a conception that solves the problem.”13 Following this line of thought, we are justified in making a moral claim if the conception it expresses solves the problem we face. Rawls’s theory justice is an example of how we construct a solution—is his case, justice as fairness – for a practical problem – in his case, how to organise social cooperation.

On both accounts, we get objective correctness criteria for categorical moral claims – without dubious metaphysical or epistemological assumptions. According to these accounts, moral claims are not true or justified independently of moral agents and agency – on the contrary, even their meaning is inextricably linked to them. But they are true or at least justified independently from any subjective desire or inclination—they are so objectively via intersubjectively realised rationality.

This is, I think, as close as we can get to moral truth. At the same time, both accounts reconcile a naturalist worldview with our realist intuitions about moral claims: We can “hope to agree with everyday moral claims, without having to take anything back”. And we can “argue that the attempt to raise further issues – Are there really any such facts? – rests on a mistake about language.“14


  • Korsgaard, C. M. (2003), ‘Realism and Constructivism in Twentieth-Century Moral Philosophy’, in: Korsgaard, C. M. (2008), The Constitution of Agency. Essays on Practical Reason and Moral Psychology, 302–326
  • Mackie, J. L. (1977), Ethics: Inventing Right and Wrong
  • Moore, G. E. (1959), ‘Four Forms of Scepticism’, in: Moore, G. E. (1959), Philosophical Papers, 220-222
  • Price, H. (2013), Expressivism, Pragmatism and Representationalism
  • Sayre-McCord, G. (2017), ‘Moral Realism’, in: Zalta, E. N. (ed.), The Stanford Encyclopedia of Philosophy (Fall 2017 Edition),
  • Sinnott-Armstrong, W. (2015), ‘Moral Skepticism’, in: Zalta, E. N. (ed.), The Stanford Encyclopedia of Philosophy (Fall 2015 Edition),


I am grateful to Matthew Braham and Florian Augustin for comments on earlier drafts of this essay.

  1. Korsgaard (2003), 302 

  2. ibid., 302 

  3. Sayre-McCord (2017) 

  4. Sinnott-Armstrong (2015) 

  5. Since Mackie (1977), such questions that invoke the strange epistemological and (see below) metaphysical status of purported moral facts are known as the “argument from queerness”. 

  6. When we put it this way, it’s easy to see that the issue for the moral realist constitutes what Huw Price calls a “placement problem” (Price 2013, 5). 

  7. Sinnott-Armstrong (2015) 

  8. When spelled out in more detail, this argument will look a lot like a reverse version of G. E. Moore’s famous argument against skepticism about the external world (Moore 1959, 222). 

  9. Price (2013), 9 

  10. Korsgaard (2003), 309 

  11. Price (2013), 32 

  12. Korsgaard (2003), 322 

  13. ibid., 322 

  14. Price (2013), 29