Naturalism and Morality: Kevin Watson on Moral Naturalism


In previous discussions, there have been a number of questions regarding how one develops a moral perspective from naturalism. Further, one issue that naturalism has to address in developing a moral framework is how one gets ought from an is - the Humean is-ought problem. For a better understanding of the sort of commitments a moral naturalist makes, we turn to Lawrence Talks! first-time contributor and University of Kansas graduate student Kevin Watson.

Kevin Watson

University of Kansas

Ph.D. Student in Philosophy

A Brief Explanation of Naturalistic Moral Realism

Naturalistic moral realism (or ‘moral naturalism’) is a meta-ethical view that combines moral realism with metaphysical and epistemological naturalism.[1] While filling in the specifics will require providing brief explanations of the theses it combines, we can characterize moral naturalism simply as claiming moral truths are deducible, definable, or explicable in terms of natural facts and properties. In other words, moral facts and properties are reducible to or supervened by natural ones.

Now, as stated above, moral naturalism combines three theses: (1) moral realism, (2) metaphysical naturalism, and (3) epistemological naturalism. According to the first of these three theses, there are objective, mind-independent moral facts. According to the second, all facts are natural. Finally, according to the third thesis, we can know moral claims are true in the same way we know claims in the natural sciences are true—by investigating the facts. In combination, these three theses entail moral statements, judgments, attitudes, and so on express propositions, we can know are true or false by investigating whether they accurately report facts the same way we investigate those made in the natural sciences. As a result, moral naturalism claims an adequate account of morality can be given without assuming the existence of anything beyond the facts of nature.

Moral naturalism is appealing for a number of reasons. For example, first, moral naturalism is able to vindicate our commonsense views of right and wrong, since it entails moral expressions are either true or false. Second, it does not commit itself to the existence of entities, qualities, or relations that J.L. Mackie claimed would be “…of a very strange sort, utterly different from anything else in the universe.”[2] Third, moral naturalism can explain why moral disagreement takes place without denying that moral utterances are truth-apt or falling victim to relativistic conundrums. Finally, fourth, moral naturalism allows us to bring our contemporary scientific worldview to bear on morality—since it claims moral facts are the same sort of things as biological, psychological, sociological, and anthropological facts.

Of course, moral naturalism is not without its critics.[3] So, briefly, there are a couple main lines of objection against moral naturalism. To begin, while it is not an objection per se, one of the more difficult problems facing moral naturalism is its ability to provide an adequate answer to the following question: What does it mean for something to be natural? Of course, this problem is faced by all naturalist theories rather than by moral naturalism alone; however, one of the worries one might have concerning moral naturalism is its assumption that the sciences do not include normative dimensions. According to the second line of objection, moral naturalism fails to appreciate the phenomenological difference between the moral and the natural. Examples of this style of argument include Hume’s Is-Ought Problem, which influenced Moore’s Open-Question Argument, the Normativity Objection, and the Triviality Objection. Finally, according to the third line of argument, you cannot make a moral judgment without being motivated to act in accordance with it. The problem, then, is that realism seems to allow cases in which you can make a moral judgment by believing some natural fact; in those cases, one could make a moral judgment without being motivated. With this brief discussion completed, let us take a closer look at Moore’s Open-Question Argument and Parfit’s Triviality Objection.[4]

First, according to the Open-Question Argument, a philosophical system claiming the possession of some natural property is going to fall victim to the following:[5]

1.      Suppose something is good if and only if it maximizes hedonic pleasure.

2.     If something is good if and only if it maximizes hedonic pleasure, the question “is maximizing hedonic pleasure good?” is meaningless (because what it means for something to be morally good is the fact that it maximizes hedonic pleasure).

3.     However, it is an open question whether maximizing hedonic pleasure is good.

4.     Thus, it cannot be the case that something is good if and only if it maximizes hedonic pleasure.

According to Lutz  and Lenman, “The point is, essentially, that [asking whether maximizing hedonic pleasure is good] is not a stupid question in the sort of way, ‘I acknowledge that Jimmy is an unmarried man but is he, I wonder, a bachelor?’ is a stupid question: if you need to ask it, you don’t understand [what it means to be a bachelor].”[6] So, on the one hand, in the case of bachelor and unmarried male, asking whether it is true whether being an unmarried male entails being a bachelor is not a sensible question—it is a misunderstanding of bachelorhood. It is analytically true that bachelors are unmarried males. On the other hand, in the case of moral goodness and hedonic pleasure (or some other natural property), asking whether it is morally good is open. Thus, Moore claims, natural properties like maximizing hedonic pleasure (or some other natural property) cannot be what goodness is. [7]

Second, Parfit’s Triviality Objection is a variation of Moore’s Open-Question Argument which claims a moral system that allows facts to be referents of both natural and moral propositions face the following:

1)     If moral naturalism is true, two claims can be about the same natural fact.

2)     Two claims about the same natural fact must contain the same information.

3)     If two claims contain the same information, the statements are equivalent

4)     Statements of equivalence are trivial.

5)     Moral claims that describe the relationships between moral facts and natural facts are not trivial at all.

6)     Therefore, moral naturalism is false.

In this second case, Lutz and Lenman claim “Parfit’s central motivating thoughts are that (a) natural-moral identity claims are substantive rather than trivial, and therefore (b) moral claims contain different information than natural claims do, which makes it plausible that (c) moral claims concern a different kind of fact.”[8] According to moral naturalism, the same moral fact can be referred to by moral propositions or natural propositions. If two claims referred to the same fact, learning the truth of the second would be trivial. However, it would not be trivial to learn a moral and natural proposition referred to the same fact.

In response to these two objections, the moral naturalist has a number of possible replies—of which one will be discussed in this paper. According to Michael Smith, if the threshold for being an analytic truth required obviousness similar to bachelors being unmarried males, then all conceptual analysis would turn out either trivial or false.[9] In other words, “the Open Question Argument seems to prove too much, being just a particular instance of the piece of reasoning embodied in the Paradox of Analysis. The practice of conceptual analysis, this reasoning goes, aspires to provide real philosophical illumination.”[10] In other words, the open question argument’s conceptual analysis of what conceptual analysis is would fail its own criteria. Arguing that conceptual analysis must meet an extremely demanding threshold entails Moore’s conceptual analysis of what it means for something to be an analytic truth is a piece of conceptual analysis unlikely to meet the threshold. Similarly, if statements of equivalence were trivial, then mathematical statements of equivalence would be. Since mathematical statements of equivalence are not trivial, statements of equivalence must not be either. Thus, both the Open-Question Argument and Triviality objection fail.

To summarize, moral naturalism is a moral realist position that claims moral statements can express true propositions if they accurately report objective, mind-independent moral facts. Additionally, as a naturalist position, it claims the ontology landscape is exhausted by the natural world. Because of the previous two claims, we can conclude that moral facts are natural and what we know about them is natural. Finally, since we can know the truth or falsity of propositions in the natural sciences by empirically investigating the factualness of their claims, we can know whether moral statements expresses true propositions the same way—by investigating the facts. What’s more, naturalistic moral realism has many appeals. Some of the appeals were outlined above; others were not. On the other hand, moral naturalism is not without its issues. Nevertheless, moral naturalism remains a promising research project in meta-ethics—one that continues to grow and mature along with, rather than in spite of, progresses made in the natural sciences.

[1] Lutz and Lenman "Moral Naturalism", The Stanford Encyclopedia of Philosophy (Fall 2018 Edition), Edward N. Zalta (ed.), forthcoming URL = <>.

[2] J.L. Mackie, Ethics: Inventing Right and Wrong (New York: Penguin, 1977), 38.

[3] I only discuss two related objections in this paper; however, other objections include the is-ought problem and fact-value distinction, the normativity objection and the motivation objection.

[4] See, Lutz and Lenman, op. cit. for a detailed discussion of both of these objections, among others.

[5] Moore, G.E., Principia Ethica, (Cambridge: Cambridge University Press, 1903),.

[6] Lutz and Lenman, op. cit., sect. 2.1.

[7] For replies to the open question argument, see Frankena (1939), Brink (1989 and 2001), Finlay and (2014); for an overview, see Lutz, op cit. sect. 2.1

[8] Op. cit.

[9] Smith, The Moral Problem, (Oxford: Blackwell, 1994).

[10] Op. cit.

A Response to Comments - Kevin Watson

Thank you for you insightful questions; I'll do my best to answer them, but I can’t promise my responses will be completely satisfying. Anyways, here it goes.

Regarding your comment that our culture is “increasingly violent,” I’d suggest taking a look at this interview with Harvard University’s Steven Pinker by scientific America. I think Pinker does a good job of explaining why this sort of thought misrepresents the facts.

Now, in response to the first line of questioning, while my statements above may have appeared to be a priori assumptions of fact, I did not intend them to be taken as such. Rather, I was presenting the discussion within a particular context. I intended my write-up to be a presentation of claims about moral naturalism in particular. For example, when I say “moral naturalism claims an adequate account of morality can be given without assuming the existence of anything beyond the facts of nature”, I am not making any assumptions about moral naturalism’s truth. Rather, I am making a claim about the view itself. While I am claiming one cannot be a moral naturalist without being a metaphysical and epistemological naturalist, that is not to say metaphysical and epistemological naturalism are true. 

In other words, while some moral naturalist or other may assume that metaphysical and epistemological naturalism are true, I am not doing so in my above post. Rather, I am attempting to present the view in an unbiased and sympathetic fashion. On the other hand, I do find the theory to be extremely plausible given the evidence we have. If pushed, I’d even be inclined to say an a posteriori investigation can only arrive at a naturalist conclusion. As Mackie rightly claims, non-natural moral facts would be very strange when compared to the types of things we experience in our everyday lives.

More to the point, there are a number of reasons one might offer in favor of metaphysical and epistemological naturalism. The main reason those sympathetic to moral naturalism are so inclined is, as far as I can tell, exactly the opposite of what you are suggesting. Whether or not any adequate theory has been given or will be given is another matter (and is largely dependent on our continued interest and investigation into moral truths). If one were to assume that metaphysical and epistemological naturalism were true a priori, one wouldn’t be a very good naturalist. I simply assumed the plausibility of these theses (but not their truth) because offering a full defense of each, in addition to having anything useful to say about moral naturalism in particular, would have been difficult given the suggested word count.

Your second line of questioning is quite interesting. However, you are asking for me to provide an answer to a question that entire books are written on. Expecting me to be able to adequately answer such a complex question on a blog post would be an unreasonable request. So, instead, I’ll simply say that when I use terms like ‘goodness’ and ‘morality,’ I am using them in the same sorts of ways that they are used in our everyday lives. Most people, it seems to me, understand what I mean when I say it is morally bad to murder and morally good to donate to effective charities. When someone says to me “it would be morally good for you to donate a portion of your income to UNICEF”, I don’t ask them how they are defining ‘goodness’ or ‘morality.’ Rather, I have a pretty clear (commonsense) understanding of what is meant.

If you wanted to know what my personal opinion is regarding what makes actions morally right or wrong, I am sympathetic to consequentialist theories of morality. In other words, if you wanted my personal opinion, I am inclined to say right actions have good consequences—where good consequences are those that promote welfare, well-being, happiness, or some number of a plurality of values that make our lives better-off.  In other words, as a consequentialist, I am inclined to say right actions are those that bring about states of affairs in which well-being, happiness, etc. are promoted at least as much as they could have been had one acted otherwise (by performing some alternative action).

In response to the third line, I find this type of question somewhat confused. Of course we can’t put goodness ‘under a microscope.’ However, much of what the sciences studies cannot be ‘put under a microscope.’ More specifically, much of what’s studied by psychology, sociology, anthropology, biology, and the like cannot be ‘put under a microscope.’ For example, when biologists study biologically altruistic traits—where the trait is deleterious to the organism that possesses the trait but beneficial to other organisms—they are looking at the biological consequences of those traits (e.g. whether the trait benefits members of the altruist’s kin-group). Likewise, when looking at actions, we can observe whether those actions have beneficial, valuable, welfare-promoting consequences or not.

Finally, you are correct that responding to Nietzsche’s argument that ‘might makes right’ is not a simple undertaking. As such, I will only offer the following: Nietzsche’s claim is false. If we look at how humanity survives and—more importantly—thrives, we find that it is when there is cooperation, care, charity, mutual respect, love, kindness, and the like; this fact about human flourishing is true whether or not the mighty claim it to be such.