Ethical Realism

April 12, 2010

A Nietzschean Argument From Disagreement: An Objection to Moral Realism

In “Moral Skepticism and Moral Disagreement: Developing an Argument from Nietzsche1 Brian Leiter argues that Nietzsche gives us a good reason to reject moral realism: Philosophers have been lead to inevitable disagreement about the foundations of ethics and we have no reason to think any of them are right. They are probably all false because “right” and “wrong” probably don’t exist. I will present Leiter’s argument as I understand it and provide my objections to it.

The Nietzschean Argument From Disagreement

John Mackie’s “argument from relativity” suggested that the best explanation for persistent moral disagreement was that moral realism is false. Nietzsche’s argument is similar to Mackie’s, but he concentrates on the persistent moral disagreement involving professional philosophers and their failure to provide a plausible foundation for moral realism. Leiter argues that widespread moral disagreement among philosophers seems to be “best explained” by moral realism being false.

Exactly what kind of disagreements are relevant? I suggest the following:

  1. Moral realists come in many varieties. There are naturalists, non-naturalists, coherence theorists, intuitionists, divine command theorists, and so on.
  2. Identifying “right” and “wrong” requires us to adopt a theory, but there are multiple theories of this kind, such as Aristotelianism, utilitarianism, Kantianism, and so on.

What is Lieter’s argument? We can summarize his Nietzschean Argument from Disagreement as the following:

  1. If any moral theory is true, then we would have probably found it by now.
  2. We haven’t found the true moral theory yet.
  3. So, it is likely that no moral theory is true.
  4. If no moral theory is true, then moral realism is false.
  5. Therefore, moral realism is probably false.

Each moral theory seems to be coherent and justified, and helps us satisfy our desire to live in a moral universe, but the theories are incompatible. They can’t all be right. Either one theory is right or all of them are wrong. Additionally, we have insufficient evidence to say which theory is probably true, so it seems reasonable to say that we have no reason to believe any of them in particular. Although each theory appears to be justified, they all appear to be so. Therefore, we can’t trust the justifications such theories require us to accept.

[Nietzsche asserts that] “all attempts to give reasons for morality are necessarily sophistical”—is established (“proved” [bewiesen] he says) by the work of the philosophers from Plato through to Kant. But in what sense do the moral philosophies of Plato, Aristotle, the Stoics, Hutcheson, Mill, Kant, and Schopenhauer et al. establish or “prove” that “all attempts to give reasons for morality are necessarily sophistical”? Nietzsche’s thought must be that all these philosophers appear to provide “dialectical justifications” for moral propositions, but that all these justifications actually fail. (Leiter)

Moreover, it seems likely that moral theories exist to satisfy our emotional needs rather than our need to understand reality. “[T]he reason it is possible to construct ‘apparent’ dialectical justification for differing moral propositions is because, given the diversity of psychological needs of persons (including philosophers), it is always possible to find people for whom the premises of these dialectical justifications are acceptable” (Leiter). To suggest that our moral beliefs are based on our psychological needs rather than facts about reality is much more simple and much less metaphysically loaded than the explanation that moral realists require us to accept.2

Leiter admits that he can’t be sure that moral realism is false, but he believes that the falsity of moral realism seems to be the best explanation for various disagreements among philosophers. That means that he must admit that one of his premises could be false, but he thinks that all the premises are very likely to be true.


I will offer two sorts of objections. One, I will consider why certain premises of the argument could be false. Two, I will consider why the argument as a whole might be misguided.

1. Why might certain premises be false?

If any premise is false, then the Nietzschean Argument from Disagreement will no longer be persuasive. I don’t know that any of the premises are false, but I don’t find them all to be completely convincing either. There is some room for doubt. Such room for doubt seriously undermines the strength of the Nietzschean Argument from Disagreement because we can’t reject very plausible beliefs, such as the belief in moral realism, unless we have even more plausible reasons to reject them.

I agree with some of the premises, but I will question premises 1 and 2.

Premise 1: If any moral theory is true, then we would have probably found it by now.

It might be that we know so little about how morality relates to reality that we wouldn’t have found a good theory for it by now. After thousands of years we only recently developed Kantianism and utilitarianism. If these moral theories offer us any insight into morality, then we can expect to make quite a bit of more progress in the future.

The progress we have made in science could be analogous to the progress we make in ethics. I imagine that there might have been quite a few theories that explained the existence of lightning before the existence of modern science. For example, lightning could be caused by light particles, fire, or Zeus’s magic javelin. Philosophers could have debated about which theory is true for thousands of years despite the fact that all of these theories are false. We simply lacked the ability to know where lightning comes from back then.

The lack of progress that seems to plague ethics could be analogous to the lack of progress found in the philosophy of mind. There are many theories to explain the existence of minds. For example, Searle’s emergence theory, Descartes’s substance dualism, and functionalism. None of these theories are entirely satisfying or justified. It seems likely that all of the theories are false. If minds are real, then they are completely unlike anything else that exists. We don’t know for sure how minds can exist, but it seems possible that we will figure it out someday. Such an understanding might require an understanding of emergence phenomena. Additionally, it seems strange to say that minds don’t exist based on persistent disagreement in philosophy of the mind considering our psychological experiences.

We might lack the ability to understand where morality comes from just like we lack the ability to understand where minds come from. If intrinsic values are a real part of the universe, then they are radically different from everything else. I have suggested that they seem likely to be an emergent part of the universe, similar to minds. If that is the case, we are currently unable to fully understand morality, but it is still possible that moral realism is true. Additionally, it seems strange to say that morality doesn’t exist based on persistent disagreement in ethical philosophy considering our experiences of benefits and harms, just like it would be strange to conclude that minds don’t exist just because we can’t explain where they come from considering our mental experiences.

Premise 2: We haven’t found the true moral theory yet.

Even if we do know all of the most plausible moral theories and we have no way to determine which one is right, we would beg the question to assert that all moral theories are false. It might be reasonable for a philosopher to reject all moral theories considering that they might all be false, but it might also be reasonable for a philosopher to adopt whatever moral theory he or she believes to be best. This doesn’t seem to be any different than how many scientists rejected string theory and others adopted string theory despite not knowing for sure whether or not it is true.

2. Is the Argument Misguided?

The Nietzschean Argument from Relativity requires us to reject the fact that there is evidence for moral realism, and such evidence does not depend on moral theory any more than the evidence that minds exist depends on theories in the philosophy of the mind. Although the specifics of moral theories could all be false, there are certain moral beliefs that seem to be “almost certainly true.” We all agree that intense pain is bad, happiness is good, torturing others willy nilly is wrong, and so on. Why do we think we are certain about these beliefs? Because of our moral experiences. We have felt that pain is bad, we have experienced that happiness is good, and we know that other people’s pain is probably bad just like our own. I have my own argument for moral realism with little to no appeal to moral theory in my essay “An Argument For Moral Realism.” The Nietzschean Argument From Disagreement in no way disproves my conclusion.

Leiter suggests that morality has no explanatory power or causal significance. That might be true if moral realism is false, but it is quite possible that we experience intrinsic values and make decisions based on those experiences. We experience that pain is bad, so we try to avoid pain when no benefit is expected to be gained from it. We know other people’s pain is also probably bad, so we decide not to harm others willy nilly, and we pass laws prohibiting torture.

Leiter’s Challenges to Moral Realism

Leiter thinks that his Nietzschean Argument from Disagreement implies three challenges to moral realism:

  1. Moral beliefs and experiences are better explained by the anti-realist than the realist.
  2. Many moral facts are undetected by philosophers.
  3. Ethical philosophers are not not coming to any sort of agreement from years of debate.

These statements could be taken to be problematic for the moral realist, but my objections already imply some possible answers to these issues:

  1. I disagree that the anti-realist can better explain our moral experiences. The anti-realist requires that “pain is bad” means little more than “I dislike pain,” but this ignores what experiencing pain is really like. We experience that pain is “bad.”
  2. I don’t know what moral facts Leiter thinks would be undetected by philosophers if moral realism is true, but I agree that foundational moral truths are undetected in the sense that we don’t entirely understand where moral facts come from. Why do we experience pain as bad? I don’t know. However, we don’t know why we have minds either. Our ignorance of foundational knowledge does not seem to imply the non-existence of entities we experience as real.
  3. Ethical philosophers have made some progress (and therefore come to a great deal of agreement). They agree that slavery is wrong, for example. However, it is true that little progress has been made concerning the origins of morality. I don’t think that is a problem for moral realism just like it’s not a problem for anyone who thinks that minds exist despite our lack of progress concerning the origins of minds.


I agree that we have a good reason to be skeptical towards moral theories and just about any other speculative philosophical theory. However, I don’t agree that there is no philosophical progress involving those theories and we might occasionally find the answer to a difficult philosophical debate. We found a pretty good answer about what causes lightning and we might someday find a good argument that explains where minds come from. Inescapable disagreement concerning the origins of lightning or minds certainly doesn’t prove that lightning and minds don’t exist. In the same way we might one day find out where morality comes from and the current disagreement involving the origins of morality doesn’t seem to imply that morality doesn’t exist in a realist sense.

Finally, we can’t conclude that the best explanation for inevitable moral disagreement concerning moral theories is that moral realism is false when we consider that moral realism has evidence in everyday life, just like the evidence that we have minds.


1 Also see Leiter’s essay “Moral Skepticism and Moral Disagreement in Nietzsche” (2009). 12 Apr. 2010. <;.


  1. Both lightning and minds can be explained via a physical explanation. Morality, if positively existent, would have no physical explanation for if it did, such as dopamine responses within the brain, then no moral agency exists.

    Comment by Evan — August 10, 2010 @ 11:27 pm | Reply

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