Home » Library » Modern Library » Michael Martin Nat Fallacy

Michael Martin Nat Fallacy

The Naturalistic Fallacy 

and Other Mistaken Arguments 

of Paul Copan (2000)

Michael Martin


Paul Copan has replied in the form of a letter[1] to my rebuttal[2] of his critique[3] of my Secular Web paper.[4] In this paper I will respond to his defense of the ontological foundation of theistic morality, his claim that ethical naturalists commit the naturalistic fallacy, his view that atheists must overcome great hurdles to make their case, his critique of the argument from evil and from nonbelief, his evaluation of my defense of the Euthyphro Argument, and his defense of the consistency of original sin and intrinsic human worth.

The Impossibility of A Theistic Ontological Foundation of Morality 

In my rebuttal I argued that theism cannot possibly be thought to be an ontological foundation of morality or anything else since the concept of God is inconsistent. I cited arguments that show there are inconsistencies in the concept of God. I argued that there is no quick way to answer these criticisms for the task will require detailed refutations of over a dozen supporting arguments. Strangely Copan does not find such an objection "threatening" (91) and makes no attempt to answer any of the prima facie inconsistencies I cited except for one brief footnote (91-92, n.2). In Atheism I argue that if God is really all knowing, He must have more than factual knowledge and must have knowing how and knowledge by acquaintance. However, I show God’s knowledge, for example, of how to ride a bike conflicts with His disembodiedness. Copan tries to escape my arguments by restricting God’s knowledge to factual knowledge. But he neglects my rebuttal. If one restricts God’s knowledge to factual knowledge, one paradoxically denies that God has all of the knowledge that human beings have.[5] In the text of his paper Copan does not attempt to reply to my arguments and only offers some programmatic remarks on how theists can avoid inconsistencies by following the Bible more carefully. How this can help when the Bible itself attributes inconsistent properties to God is not explained.[6]

Naturalistic Metaethics 

Copan’s argument against naturalistic metaethics is elusive. In his earlier paper his complaint seemed to be that naturalistic ethics cannot have an ontological foundation. In my reply to Copan I explained that naturalists say it has a naturalistic ontological foundation; that is, they say that moral properties are constituted by natural properties. In his letter Copan seems to have modified his criticism. Naturalists such as Firth, Boyd, Brink and Railton, Copan now says, are committing the naturalistic fallacy (NF) by inferring "ought" from "is." However, as William Frankena pointed out long ago, to say that someone commits the NF begs the question.[7] It assumes what it must prove, namely, that factual statements never entail ethical statements. But if moral terms mean the same as natural terms, one can infer "ought" from "is". Naturalists such as Firth have proposed definitions of "ought" in terms of "is". These cannot be easily refuted since the postulated meaning relation between "ought" and "is" may be covert or opaque. 

In addition, even if it were a fallacy to infer "ought" from "is," this would not defeat naturalism. Naturalists need only claim that moral properties are constituted by natural properties — no meaning relation between "ought" and "is" has to be assumed. In this case naturalism would infer normative statements from factual statements only when factual statements were combined with bridge statements specifying a contingent relation between moral and natural properties. Such bridge statements would be justified by how well they cohere with other statements and how well they explain our moral experience. It is dubious, therefore, that NF can be used to refute naturalistic ethics. One must look at particular arguments in detail to see if some specific mistake has been made. Unfortunately, Copan seems disinclined to do this. Indeed, it is unclear to me that Copan has even read some of the naturalistic ethicists I have cited. For example, Brink devotes an entire chapter in his book to the is-ought issue[8] yet Copan seems unaware of Brink’s arguments and merely dismisses his point concerning the supervenience of the mental on the physical. 

In his remarks on Firth’s Ideal Observer Theory (IOT) Copan also seems confused. He admits that the IOT is compatible with atheism but he pounces on Charles Taliaferro’s statement that the IOT is also compatible with moral skepticism and assumes that this remark is a decisive point against me (92). However, Taliaferro’s claim is that someone might accept the lOT analysis and yet maintain that it is impossible to know what an Ideal Observer would approve of and thus to know what was morally right and wrong. Let us call this moral epistemic skepticism (MES). Notice that Taliaferro is not saying the IOT is committed to MES but is only maintaining that it is possible to hold MES and the IOT. More importantly, Taliaferro is not saying that IOT is compatible with moral ontological skepticism (MOS) — that is with skepticism about whether there are moral facts constituted by natural facts. Indeed, it is difficult to see how one can hold MOS and yet accept the IOT since on Firth’s analysis moral properties by definition are constituted by certain natural facts.[9] But why should one accept Firth’s theory? As a semantic theory it is acceptable if the Ideal Observer analysis captures what we mean by key moral expressions. Copan gives no reason to suppose it does not do this. Indeed, he does not even try to show this.

Copan’s Hurdles

In addition to claiming that naturalists have committed the NF Copan argues that they have a number of hurdles to overcome in order to prove their case. These run from explaining the origin of the universe to accounting for the emergence of sentient life. Copan’s treatment here ignores all the excellent critiques that naturalists have given of theistic interpretations of these phenomena. One of the hurdles Copan lists has to do with the numerous conditions that must be in delicate balance in order to have a life-permitting and life-producing universe. Presumably he is appealing to the Fine Tuning Argument, which normally proceeds from this delicate balance to the conclusion that only theism can account for it. However, instead of drawing this theistic conclusion, Copan asked me the rhetorical question: "Is there not such a remarkable complexity in the universe that a supernatural explanation warrants deeper personal investigation (96)?" He should know that after giving deep thought to this argument I have rejected it. In my Internet review of Patrick Glynn’s God: The Evidence I raised critical questions about the sort of data Copan is implicitly appealing to.[10] Given that review I might in turn ask Copan the rhetorical question: "Is it not obvious that this complexity has no evidential import regarding the truth of theism?"

Copan’s Dismissal of the Argument from Evil (AE) and the Argument from Nonbelief (ANB).

In my reply to Copan’s critique I pointed out that Copan failed to note that there are facts such as the existence of evil and widespread nonbelief which prima facie count against theism. His attempt to deal with these points in his letter is unsatisfactory. First, he maintains that if a good God exists, then we have grounds for thinking that the AE can be answered. Perhaps. But where has Copan established the existence of a good God? Second, Copan seems to suppose that our awareness of evil points in "the direction of theism (98)". This is nonsense. Even if Copan had showed that naturalistic morality could not have the concept of evil, theism is no more probable than other supernaturalistic theories. For example, a powerful evil being might bring about our awareness of evil in order to cause us anguish. Copan tries to answer the ANB by using the free will defense (FWD): if God made more strenuous efforts to get people to believe in Him, God would be coercing belief and not allowing for free will. But Drange has shown FWD to be unsound. God could do many things to increase belief without interfering with free will.[11]

The Euthyphro Argument

In his response to my comments on the Euthyphro Argument, Copan either ignores or misunderstands almost everything that I said. Recall that according to this argument either morality is not dependent on God or else morality is arbitrary and thus God could make wanton cruelty good. The Essential Moral Attribute Response (EMAR) maintains that God has essential moral attributes that determine what is right or wrong. Hence, morality is not arbitrary. But morality is not independent on God either since morality could not exist independently of God. I gave no less then seven arguments against EMAR:[12]

(1) EMAR conflicts with a common view of God.

(2) It does not follow that if a property is an essential property of God, it could not exist without God.

(3) There is no contradiction in denying God and asserting that there are moral facts.

(4) There is no good argument that moral facts are improbable in a godless universe.

(5) It is a fallacy to argue that if a moral attribute is an essential property of God, then it is a moral attribute because of this.

(6) Naturalistic objective ethical theories remain unrefuted.

(7) The view that morality depends on God conflicts with our well-supported judgments that the torture of babies is wrong.

Copan does not begin to answer all these points. I have already pointed out the problems in Copan’s answer to (6). His attempt to answer (3) is confused in turn. He seems to assume that (3) is intended to make the epistemic point that one cannot know what to do morally without knowledge of God. Since, however, he is making an ontological point, not an epistemic one, he rejects (3) as irrelevant (100). But, of course, (3) is making an ontological point: the nonexistence of God is logically compatible with the existence of moral facts. He seems to argue against (7) on similar grounds. However, (7) is not just about epistemology. The problem is not just about the knowledge that the torture of babies is wrong. It is about a moral fact that we know exists independently of God. This become clear when it is noted that there is no inconsistency in saying we have this moral knowledge and yet know God does not exist. Copan goes on at great length about the arbitrariness of atheistic morality and asserts that in an atheistic worldview there would be no reason not to have slavery. But, of course, if any of the naturalistic ethical views previously considered are true, there would be good reasons. And, as we have seen, Copan’s question begging arguments do not refute naturalistic ethics. Ironically, Copan assumes that religion advocates the immorality of slavery and he cites the New Testament (100) to support his views. Yet one of the biggest scandals of Christian ethics is that Jesus and his disciples did not speak out against slavery and seemed tacitly to approve of it.[13]

Human Worth and Original Sin

Copan says that on the Christian view human beings have intrinsic dignity and worth. He agrees with me that in fact many Christians maintain that humans are worthless sinners, but finds no contradiction since sinfulness is "accidental" rather than essential to human nature. Copan’s accidental interpretation of human sin is certainly not the way it is understood by many Christian thinkers, but for the sake of the argument let us accept it. Unfortunately, his essential-accidental distinction does not help overcome the inconsistency. Let us understand an essential property P of X to be one that it has necessarily. So the statement "X is P" is necessarily true. Let us understand an accidental property Q of X as one that is not essential. So the statement "X is Q" is contingently true. Someone who says that human beings have intrinsic worth is saying: 

(1) "Humans have intrinsic worth" is necessarily true.

Someone who claims that human beings are worthless sinners is saying:

(2) "Human beings have no intrinsic worth" is contingently true.

But (1) and (2) combined entails an inconsistency:

(3) Human beings have intrinsic worth and have no intrinsic worth.

Since (3) is an inconsistent statement, making the distinction between necessary and accidental properties does not show that the Christian view is coherent.


Copan’s letter, "Atheistic Goodness Revisited: A Personal Reply to Michael Martin," has the same problems as his paper "Can Michael Martin Be A Moral Realist? Sic et Non". Copan’s critique of atheistic metaethics is mistaken. Moreover, his defense of a theistic based ethics is unsound. In short, he has given no reason to reject atheism or to accept theism.


[1] Paul Copan, "Atheistic Goodness Revisited: A Personal Reply to Michael Martin" Philosophia Christi, Series 2, Vol. 2,2000, pp. 91-104. In the remainder of my paper page references to this paper will be in the body of the text.

[2] Michael Martin, "A Response to Paul Copan’s Critique of Atheistic Objective Morality," Philosophia Christi, Vol. 2,2000, pp. 75 -90.

[3] Paul Copan, "Can Michael Martin Be A Moral Realist? Sic et Non," Philosophia Christi, Series 2, Vol. 1, No. 2, pp. 45-71.

[4] Michael Martin, "Atheism, Christian Theism, and Rape," July 23, 1997, /library/modern/michael_martin/rape.html 

[5] Michael Martin, Atheism (Philadelphia, PA: Temple University Press, 1990), p. 289.

[6] Theodore Drange, Nonbelief and Evil (Amherst, NY: Prometheus Books, 1998), pp.80-82.

[7] See William Frankena, "The Naturalistic Fallacy," Mind, 48, 1939 reprinted in Readings in Ethical Theory, (ed.) Sellars and Hospers, pp. 54-62.

[8] David O. Brink, Moral Realism and The Foundations of Ethics (Cambridge University Press, 1989), Chapter 6.

[9] In a similar way one might be a moral epistemic skeptic with respect the Divine Command Theory and still accept this theory.

[10] /library/modern/michael_martin/glynn.html

[11] See Theodore Drange, Evil and Nonbelief (Amherst, NY: Prometheus Books, 1998), Chapter 5.

[12] Martin, "A Response to Paul Copan’s Critique of Atheistic Objective Morality," pp. 83-85.

[13] Michael Martin, The Case Against Christianity (Philadelphia, PA: Temple University Press, 1991), p. 168.


all rights reserved