Is Ethics Without God Possible? An Answer, Plus Some Thoughts, About the Question

Abstract

Is Ethics Without God Possible? In this article, I argue for the conclusion that ethics without God is possible. First, I begin by offering a brief overview of metaethics, outlining the main options concerning the nature of ethical statements. Next, I set out my argument. As it turns out, that argument does involve some philosophy of religion, but of a limited scope, since the only issue relevant to my argument is whether some version of the ontological argument for the existence of God is sound or not. Finally, having argued that ethics without God is possible—leaving aside the minor qualification mentioned above—I shall indicate why I think it is crucial to consider how philosophy of religion might bear upon the question initially posed, and thus why it is a mistake to address the question posed without considering how philosophy of religion might bear upon the question initially posed.

The philosophical question that has been posed is whether ethics is logically possible if God does not exist, and the objective is to defend a clear “Yes” or “No” answer to that question.

This is clearly an important question, since in contemporary philosophy of religion there are several arguments against the existence of God that appeal to the existence of evil in the world that have never been satisfactorily answered, including arguments that claim that the existence of evil in the world is logically incompatible with the existence of God, advanced by Schellenberg (2013, 2018), Sterba (2019) and Sterba and Swinburne (2024); Humean style evidential arguments from evil advanced by Draper (1989) and Tooley (2011) and equiprobability-principle based arguments advanced by me in Tooley and Plantinga (2008) and Tooley (2019).

If any of these arguments is successful, then, if ethics without God were not possible, the result would be disastrous, since it would follow that morality was without any foundation. I shall be arguing, however, that ethics without God is logically possible.

My conclusion will involve, however, a slight qualification. Should not my answer be viewed, then, as a failure to meet the challenge? Well, technically, that is certainly true. The situation, however, is as follows. In his book Ethics: Inventing Right and Wrong, J. L. Mackie (Mackie 1977) set out several arguments in support of what is known as an “error theory”, according to which no positive statements about states of affairs being good or bad, or about actions being right or wrong, can ever be true, and the problem is that I do not think that anyone has ever set out a convincing refutation of that view.

Notice, however, that if Mackie is right, then while ethics without God is logically impossible, the same is true as regards ethics with God: either way, ethics is dead in the water.

Hopefully, some readers will be able to provide a knock-down refutation of Mackie’s error theory. Supplementing my argument with such a refutation would then yield a proof that ethics without God is possible.

1. The Structure of My Discussion

The question whether ethics without God is possible involves two areas of philosophy, namely, ethics and philosophy of religion—areas that, moreover, are not normally closely related. I believe, however, that in thinking about the question posed, it is important to consider whether knowledge of philosophy of religion may be relevant. I shall argue later that it is.

My essay is structured as follows. First, I offer a brief overview of metaethics, outlining the main options concerning the nature of ethical statements.

Next, I set out my argument. As it turns out, that argument does involve some philosophy of religion, but of a limited scope, since the only issue relevant to my argument is whether some version of the ontological argument for the existence of God is sound or not.

Finally, having argued that ethics without God is possible—leaving aside the minor qualification mentioned above—I shall indicate why I think it is crucial to consider how philosophy of religion might bear upon the question initially posed, and thus why it is a mistake to address the question posed without considering how philosophy of religion might bear upon the question initially posed.

2. Metaethics: A Brief Overview

One of the most fundamental tasks throughout different areas of philosophy is that of analyzing philosophically crucial concepts—such as, in epistemology, the concepts of knowledge, belief, justification, probability, direct and indirect awareness; in philosophy of mind, the concepts of mental states, consciousness, the mind, beliefs and desires; in metaphysics, the concepts of causations, laws of nature, dispositions, identity over time, and so on.

Let us turn, then, to the question of what account can be given of the meaning of ethical statements, including terms such as “right” and “wrong”, “good” and “bad”, “ought” and “ought not”. Here I want to suggest that different views in metaethics can be seen as falling into four groups: (1) non-propositional views; (2) Reductionist views; (3) non-reductionist views, and (4) Moral skepticism, also known as the Error Theory

2.1. Non-Propositional Views of Ethical Statements

This first group of views are often described as non-cognitivist theories. That terminology seems to me unhappy, since cognition is the act of acquiring knowledge, and therefore to use the term “non-cognitivist” is to risk muddling together the question of whether the meaning of ethical statements is compatible with the possibility of moral knowledge with the logically prior question of the semantic nature of moral statements. The starting point, accordingly, should be with the question of whether ethical sentences express propositions, and thus are either true or false.

Turning, then, to the meaning of ethical statements, several well-known philosophers, among them the following, have defended the view that ethical statements do not express propositions. Thus, A. J. Ayer in Language, Truth, and Logic (Ayer 1936) advanced the view that ethical statements express certain emotions directed toward or against various actions, while R. M. Hare (1952) argued instead, in The Language of Morals, that ethical statements are prescriptive statements, telling one to perform, or not perform, certain types of actions. Similarly, Rudolf Carnap, though not widely known for his work in ethics, also advanced the view that ethical statements, rather than expressing propositions—and also rather than being either emotive utterances or imperatives—were what he described as “optative” in nature:

There is a general kind of meaning common to all statements expressing a wish, a proposal, a request, a demand, a command, a prohibition, a permission, a will, a decision, an approval, a disapproval, a preference, or the like, whether or not they also contain meaning components referring to matters of fact. I shall use the term “optative” for this general kind of meaning. I shall call a sentence which, among others, has a meaning component of this kind an “optative sentence” or for short “an optative”. Thus, I’m using the term “optative” in a much wider sense than is customary, since there is no term in common use for the intended general sense. The term “emotive” is inappropriate, as mentioned above. The term “imperative” is often used in a generalized sense by philosophers; in such cases, my term “optative” may be regarded as nearly synonymous with it. The term “optative” seems more suitable than the term “imperative” because the conventional meaning of “wish” is wider than that of “command”. If I express disapproval of someone’s action, then my expression contains the wish, though unfulfillable, that he had not done it. An expression in imperative form would not make sense in this case. Proposals, requests, commands, etc., may be regarded as various modes of optatives.

(Carnap 1963, p. 1001)

What is one to say about such views? It seems to me that, viewed as accounts of the actual meaning of ethical language, they are deeply implausible. For suppose that you ask someone, “Is it true that it is ‘prima facie’ wrong to torture someone?” or “Is it true that being in pain is itself a bad state of affairs?” Would not the vast majority of people answer “Yes” to such questions? If so, then people in general view claims about the rightness and wrongness of actions, and the goodness and badness of states of affairs as having a truth-value, and thus as expressing propositions.

If this is right, then it seems that one should view non-propositional views of ethical statements not as possible accounts of the actual meanings of such statements, but as instead reflecting sceptical views concerning the possibility of objective moral truths, and therefore advancing proposals concerning how such sentences might profitably be reinterpreted.

2.2. Ethical Statements Can Either Be Analyzed in Terms of, or in Some Other Way Be Reduced to, Descriptive Propositions That Involve No Explicitly Ethical Concepts

This approach to ethical statements comes in two very different forms. First of all, there is moral naturalism, according to which moral facts are simply certain facts about the natural, purely spatiotemporal world.

Second, there is ethical supernaturalism, according to which moral propositions involve reference to a person who is something over and above the physical, spatiotemporal world. It would be natural, then, at this point, to bring in the concept of God.

As the term “God” is generally understood, doing that is immediately ruled out, since the term “God” is usually defined as an omnipotent, omniscient, and perfectly good person, and then one will not be able to either analyze or reduce ethical concepts and statements to purely descriptive concepts that have no ethical content.

Here, however, one can follow the lead of William Lane Craig (2009) and get a theologically based approach to ethics that is an alternative to moral naturalism, however the latter is formulated, by eliminating the term “good” from one’s definition of the term “God”, as William Lane Craig, for example, does in the following passage:

First, if theism is true, we have a sound basis for objective moral values. To say that there are objective moral values is to say that something is good or evil independently of whether anybody believes it to be so. It is to say, for example, that the Holocaust was morally evil even though the Nazis who carried out the Holocaust thought that it was good.

On the theistic view, objective moral values are rooted in God. He is the locus and source of moral value. God’s own holy and loving nature supplies the absolute standard against which all actions are measured. He is by nature loving, generous, just, faithful, kind, and so forth. Thus if God exists, objective moral values exist.

(Craig 2009, p. 30)

Craig’s approach to ethics, by employing a characterization of God that does not involve any explicitly ethical language—such as the concept of being perfectly good—gives one, then, a supernaturalistic approach to the foundations of ethics that is free of any circularity.

As regards the general view that ethical statements can either be analyzed in terms of, or in some other way be reduced to, purely descriptive propositions that involve no explicitly ethical concepts, does one therefore need, at this point, to consider such an approach?

The answer is that one does not, since the argument that I shall offer later in support of the view that ethics without God is logically possible, provided that Mackie’s error theory is not true, will also show that a supernaturalistic approach to ethics based on Craig’s strategy cannot provide a satisfactory foundation for ethics.

In addition, ethical supernaturalism is exposed to very serious objections based on the horrendous evils that one finds in the world. Thus, one has arguments that claim that the evil that exists in the world is logically incompatible with the existence of an omnipotent, omniscient, and morally perfect deity—arguments that have been advanced by J. L. Schellenberg (2013, 2018) and by James Sterba (2019) and Sterba and Swinburne (2024). Then there are probabilistic arguments against the existence of God, including Humean-style evidential arguments, advanced, for example, by Paul Draper (1989, 2014), and Michael Tooley (2011), and equiprobabilty-principle based evidential arguments from evil advanced by me in Tooley and Plantinga (2008) and Tooley (2019).

These arguments have typically been directed against the God of classical theism, understood as omnipotent, omniscient, and perfectly good. It would be surprising, however, if they had any less force when the term “God” is used instead, as William Lane Craig does, to refer to an omnipotent and omniscient being who is loving, generous, just, faithful, and kind.

Let us turn, then, to moral naturalism. The first point that needs to be made is that this label covers a plethora of views, as the Stanford Encyclopedia of Philosophy entry “Moral Naturalism,” (Lutz 2024) by Mathew Lutz, which is almost 17,000 words in length, makes clear. One important distinction, for example, is that while some forms of moral naturalism offer analyses of ethical statements, other forms do not. Sometimes the view, for example, is instead that the relation between moral properties and purely descriptive properties is like that between the concept of being water and the concept of being H2O, where the latter is not an analysis of the former. Alternatively, the idea of an analytical relation is sometimes replaced by what seems to me one of the most obscure ideas in all of metaphysics—the idea of grounding—so that the claim is then that ethical properties are grounded in purely descriptive concepts.

Regardless of how moral naturalism is interpreted, however, it clearly poses no problem for the thesis that ethics without God is possible, since it entails that ethics without God is possible.

2.3. Is the Analytic Form of Ethical Naturalism Tenable?

Consider the axiological propositions that pain is intrinsically bad and pleasure is intrinsically good. Can one arrive at those propositions by analyzing the concepts of pain and pleasure? Well, both of those concepts can be analyzed. First of all, one is immediately aware of states of consciousness, so one has direct knowledge of what states of consciousness are. Second, given the notion of causation, which can be given a theoretical term analysis, one can explain what it is for an organism to be disposed to bring about a state of consciousness, and being disposed to prevent, or to terminate, a state of consciousness. A pleasurable state of consciousness can then be defined as a state of consciousness that an organism is disposed to bring about, while a painful state of consciousness is one that an organism is disposed to prevent or to terminate. Then perhaps the idea is that a good state of affairs can be defined as a pleasurable state of affairs, and a bad state of affairs as one that is painful.

Consider, however, one’s continued existence during a time when one is not experiencing either pleasure or pain. Most people, surely, would think that such a state of affairs is a good one, even though one is not in a pleasurable state. But it is nevertheless something that most people would strongly prefer to the non-existence of that state. This suggests that it would be better to define a good state of affairs as one where the person in that state prefers its presence to its absence, while a bad state of affairs is one whose non-existence the person involved in that state would prefer to its presence.

The upshot is that a naturalistic account of the goodness and the badness of states of affairs certainly deserves serious consideration.

But what about deontological propositions, such as that it is prima facie wrong to inflict pain upon other sentient beings? One also needs an account, however, not just of the goodness and badness of states of affairs, but also of the rightness and wrongness of actions, and here, I think, nothing very plausible springs to mind.

If it were true that humans were naturally disposed to not inflicting pain on other sentient beings, then perhaps one could hold that the idea of an action’s being prima facie morally wrong could be analyzed as an action’s being one of inflicting pain on another sentient being. But is it true that humans are innately so disposed? Isn’t it the case, rather, that the extent to which people have such a disposition depends on how they were raised?

Well, the above is all rather speculative, and the question of whether some form of ethical naturalism is correct is especially difficult given the many different forms of ethical naturalism that have been advanced. The crucial point here, however, is simply that if some form of ethical naturalism is true, it entails the conclusion that ethics without God is possible.

2.4. Is the Non-Analytic Form of Ethical Naturalism Tenable?

Here, the idea is that it is not an analytic truth that all water is H2O, but that is nevertheless a necessary truth that all water is H2O. So, there are necessary truths that are not analytic truths. Why, then, could that not be the case for basic moral truth?

This does not seem to be a promising line of thought. A liquid is classified as water on the basis of observable properties: water is a clear, colorless, odorless, and tasteless liquid, having a freezing point of 32 degrees Fahrenheit and a boiling point of 212 degrees Fahrenheit. Scientific investigations then give rise to the atomic theory of matter, and it is found that a water molecule consists of two hydrogen atoms and one oxygen atom held together by what are known as chemical bonds.

In short, the necessary truth that water is H2O is the result of scientific investigations and theorizing. There is nothing comparable in the case of moral truths, so the non-analytic version of ethical naturalism does not seem plausible.

2.5. Conclusions

If ethical naturalism were correct, that would have the desired feature of entailing that ethics without God is possible. However, neither the analytic nor the identity form of naturalism seems plausible. It would seem, therefore, that one must look elsewhere for a satisfactory foundation for ethics.

3. A Non-Reductionist Approach: Ethical Intuitionism

Let us now turn to the view often referred to as “ethical intuitionism.” So, first of all, what are “ethical intuitions”? Michael Huemer, in his book Ethical Intuitionism, offers the following, very clear answer:

Reasoning sometimes changes how things seem to us. But there is also a way things seem to us prior to reasoning; otherwise reasoning could not get started. The way things seem prior to reasoning we may call an ‘initial appearance’. An initial, intellectual appearance is an intuition. That is, an intuition that p is a state of its seeming to one that p that is not dependent on inference from other beliefs and that results from thinking about p, as opposed to perceiving, remembering, or introspecting. An ethical intuition is an intuition whose content is an evaluative proposition.

(Huemer 2005, pp. 101–2)

Now, Huemer argues that intuitions in general can justify one in believing that the proposition in question that seems to one to be true is true. But one can ask about what the relevant truthmaker is. What is it that makes it the case that it is true?

Consider, then, the proposition that all pain is an intrinsically bad state of affairs. Assume that this statement is true. If so, surely it must be a necessary truth. But compare it with the following familiar necessary truth: All bachelors are unmarried. In the case of the latter proposition, what makes it a necessary truth is that given that the definition of a bachelor is, say, the concept of an unmarried male human of marriageable age, if one substitutes that into the sentence in question, the result is the sentence “All unmarried male humans of marriageable age are unmarried”. This, of course, is a logical truth, which means that the original sentence “unmarried male human of marriageable age is an analytically true proposition”.

The proposition “Pain is an intrinsically bad state of affairs,” by contrast, is not an analytically true proposition. It is what is commonly referred to as a “synthetic a priori” proposition. The result is that ethical intuitionism is committed to the view that there are synthetic a priori propositions.

3.1. Is This Commitment Problematic?

Is the need to invoke the idea of synthetic a priori propositions a serious objection to ethical intuitionism? The most common way of arguing that it is not the case is by citing what are claimed to be necessarily true statements that have no ethical content but that are not analytic truths, such as “Nothing can be both red all over and green all over.”

What is one to say about this argument? The question to ask is, “What types of necessary truths are there?” First, there are logical truths. Second, there are analytically true propositions, where these are propositions such that if all the terms in the proposition that are not analytically basic are replaced by the relevant analyses, the results are truths of logic. Leaving aside the possibility of synthetic a priori propositions, are there any other candidates? Mathematical propositions are one important candidate, but the question is whether logicism, according to which mathematical truth can be derived from logical truths, has been completely ruled out.

Another candidate is the proposition that anything that exists must have properties, but that’s a controversial case. Moreover, I am interested in “types” of propositions that have more than one member.

Here, in any case, is a type of proposition where I think that it is plausible to hold that it is a type of proposition that one is justified in believing is necessarily true. Consider property dualism—a view for which there are three famous types of arguments. First, there was Thomas Nagel’s article, “What is it like to be a bat?” in Nagel (1974). This was followed by Frank Jackson’s famous “Mary” argument–also known as the “knowledge” argument—set out in “Epiphenomenal Qualia” (Jackson 1982) and then defended further in Jackson’s “What Mary Didn’t Know” article (Jackson 1986). Finally, there is David Chalmers’ “Zombie” argument, set out in his book The Conscious Mind–In Search of a Fundamental Theory (Chalmers 1996).

Now I believe that property dualism is true. However, my suggestion requires only that property dualism is not necessarily false, and the argument is as follows. Assume that property dualism is true, and that you are looking at a ripe tomato and some peas. Then you are immediately aware of the phenomenal properties redness and greenness, and because the properties you are aware of are phenomenal properties, they necessarily are as they appear to be, and whatever physical properties they causally depend on makes no difference to the phenomenal properties in question: their complete nature is present in your experience (Tooley 2013).

But given that the complete nature of phenomenal properties is given in your experience, is it not true that you can just see that redness is not only different from greenness, but that phenomenal redness and phenomenal greenness are incompatible properties, so that nothing could be both totally red and totally green at the same time?

The upshot is that propositions such as that nothing can be both red all over and green all over do not provide grounds for concluding that there are synthetic a priori truths. Accordingly, the question of whether the idea of synthetic a priori truths is acceptable, or problematic, would seem to remain unsettled.

3.2. Crucial Objections to Ethical Intuitionism?

Central to Michael Huemer’s defense of ethical intuitionism is the concept of something’s seeming/appearing a certain way. Huemer, however, does not offer any account of the concept of seeming, and his reason he doesn’t, as he says in the opening paragraph of Phenomenal Conservatism Über Alles, is that “Despite the popularity of the school of linguistic analysis in twentieth-century philosophy, I cannot name a single analysis of any philosophically interesting term that has not been refuted.” (Huemer 2013, p. 328)

It is certainly true that philosophy is littered with failed attempts to provide satisfactory analyses of important philosophical concepts. I do think, however, that there are exceptions. In any case, I think that when one says that it seems to them, or appears to them, that something is the case, then either the proposition in question refers to something of which they are directly aware, such as a present visual experience, or the proposition is one for which they have good evidence, or the proposition in question is analytically true, or else, finally, that the proposition is simply one that they are inclined to believe, but for which they can offer no support.

Synthetic a priori propositions fall under the final category, and according to ethical intuitionism, basic ethical principles are synthetic a priori propositions. Can one, then, offer any general account of when a synthetic a priori proposition is reasonable? That is probably a challenging task. But can one at least offer reasons for questioning the reliability of ethical intuitions?

Consider holding slaves, which is surely an extraordinarily immoral action. But when was slavery first abolished? According to Wikipedia (2025a), “The first country to fully outlaw slavery was France in 1315, but it was later used in its colonies. The first country to abolish and punish slavery for indigenous people was Spain with the New Laws in 1542.” Is it plausible, then, that, during the long preceding stretch of human history, it seemed to people that slavery was morally wrong? The answer, I suggest, is that that is not plausible. But then how can one be justified in holding that ethical intuitionism is true if the relevant intuition seems not to have been present in the case of slavery, which is deeply immoral?

In response, however, it might be argued that the slavery example may oversimplify the relation between moral intuitions and social practices, since historical acceptance of slavery does not necessarily entail the absence of moral discomfort or dissenting intuitions. The thought here is that such intuitions may have been suppressed by cultural, economic, or political pressures. Finally, the eventual abolition of slavery could be interpreted as evidence of the progressive refinement or articulation of moral intuitions over time, rather than their unreliability.

This is certainly something that needs to be considered. In the next section, I shall be considering moral skepticism, a view defended by J. L. Mackie, according to which no positive moral propositions are true. As we shall see, Mackie advanced several arguments in favor of moral skepticism, the first of which is very relevant here, and which involved “the relativity or variability of some important starting points of moral thinking, and their apparent dependence on actual ways of life.” Here, the point is that if one considers moral teachings at other times and places, one finds many examples, besides slavery, where people embraced moral views that now seem to most people quite extraordinary. Consider, for example, what the Old Testament has to say should be done in the following situations: (1) A woman who is not a virgin gets married (Deuteronomy 22:20–21); (2) A man lies with another man as with a woman (Leviticus 20:13–14); (3) A man has sexual intercourse with a woman and then, at some, possibly much later point in time, with the woman’s mother (Leviticus 20:14); (4) A person commits adultery (Leviticus 20:10, also Deuteronomy 22:22); (5) Parents have a rebellious son (Deuteronomy 21:18–21). In all of these cases, the answer is that the people who are viewed as having done something morally wrong should be killed.

Moreover, one does not have to dive into the ancient past to find cases where laws were present that now seem to most people ethically unacceptable. For example, according to Wikipedia (2025b), “Prior to 1962, sodomy was a felony in every state, punished by a lengthy term of imprisonment or hard labor.”

It seems to me that it is hard to square such historical facts with the views that basic moral propositions are synthetic a priori truths and that humans have a faculty of intuition that allows them to grasp those truths.

Finally, however, if, contrary to what I have just suggested, ethical intuitionism turned out to be correct, that would be welcome as regards my argument for the conclusion that ethics without God is possible, since it would mean that the small qualification otherwise attached to my argument could then be dropped.

4. Moral Skepticism, Aka the Error Theory

According to the error theory, set out by J. L. Mackie in his book Ethics: Inventing Right and Wrong, no positive moral proposition is true, where a positive moral proposition includes both (1) axiological propositions asserting that certain specific types of states of affairs are good, or desirable, or that other specific types of states of affairs are bad, or undesirable and also (2) deontological propositions, which affirm that certain types of actions are morally wrong, or that certain other specific types of actions are morally required.

Here is a passage in which Mackie not only explains his error theory very clearly, but also summarizes the types of arguments that can be offered in support of it—arguments that he set out in a very detailed way earlier in his book:

I have maintained that there is a real issue about the status of values, including moral values. Moral scepticism, the denial of objective moral values, is not to be confused with any one of several first order normative views, or with any linguistic or conceptual analysis. Indeed, ordinary moral judgments involve a claim to objectivity which both non-cognitive and naturalist analyses fail to capture. Moral scepticism must, therefore, take the form of an error theory, admitting that a belief in objective values is built into ordinary moral thought and language, but holding that this ingrained belief is false. As such, it needs arguments to support it against ‘common sense’. But solid arguments can be found. The considerations that favor moral scepticism are: first, the relativity or variability of some important starting points of moral thinking, and their apparent dependence on actual ways of life; secondly; the metaphysical peculiarity of the supposed objective values, in that they would have to be intrinsically action-guiding and motivating; thirdly, the problem of how such values could be consequential or supervenient upon natural features; fourthly, the corresponding epistemological difficulty of accounting for our knowledge of value entities and features and of their links with the features on which they would be consequential; fifthly, the possibility of explaining, in terms of several different patterns of objectification, traces of which remain in moral language and moral concepts, how even if there were no such objective values people not only might have come to suppose that there are but also might persist firmly in that belief. These five points sum up the case for moral scepticism; but of almost equal importance are the preliminary removal of misunderstandings that often prevent this thesis from being considered fairly and explicitly, and the isolation of those items about which the moral sceptic is sceptical from many associated qualities and relations whose objective status is not in dispute.

(Mackie 1977, pp. 48–49)

The upshot is that the precise thesis that I shall be defending is this: if Mackie’s error theory is wrong, then ethics without God is logically possible.

5. An Argument for the View That Ethics Without God Is Logically Possible, Provided That Mackie’s Error Theory Is Not True

First, before setting out the argument, some distinctions. Ethics involves two parts: metaethics and normative ethics. The former concerns the general nature of ethical statements—for example, whether they express propositions, and thus are either true or false, or whether they function in some other way, such as expressing emotions, such as A. J. Ayer claimed in Language, Truth, and Logic, or whether they are prescriptive statements, as R. M. Hare argued in The Language of Morals.

Normative ethics, on the other hand, is concerned with deontological propositions, such as whether some type of action is morally right or morally wrong, and with axiological propositions, such as whether some state of affairs is desirable or undesirable, intrinsically good or intrinsically bad.

My initial argument will assume that ethical statements do express propositions, and thus are either true or false. So, it involves the assumption that Ayer’s emotivist theory, and Hare’s prescriptivist theory, along with other non-propositional approaches in metaethics, are unsound accounts of normative statements, and it also involves the assumption, which I do not believe has ever been shown to be true, that Mackie’s error theory is false.

5.1. Step 1 in the Arguments: The Existence of Moral Truths

Assume that, contrary to Mackie’s error theory, there are moral truths.

5.2. Step 2 in the Argument: The Existence of Moral Truths That Do Not Entail the Existence of God

Consider the axiological proposition that pain is intrinsically bad. That statement does not logically entail the existence of God. Similarly, compare the deontological principle that the killing of neo-Lockean persons is intrinsically wrong. That statement also does not logically entail the existence of God.

5.3. Step 3 in the Argument: The Logical Status of Basic Ethical Truths—Propositions That Are True in Every Possible World

Some true ethical propositions are not necessary truths. Consider, for example, the ethical proposition that pulling a cat’s tail is wrong. There are propositions that, though false as things stand, could have been true, and that, if true, would support the conclusion that pulling a cat’s tail is not wrong—such as the proposition that cats do not even notice when their tails are being pulled, or the proposition that cats enjoy having their tails pulled. Consequently, the true moral proposition that pulling a cat’s tail is wrong cannot be a necessary truth.

Contrast the situation in the case of the axiological proposition that pain is intrinsically bad, or with the deontological principle that the killing of neo-Lockean persons is intrinsically wrong. Those propositions, assuming that Mackie’s error theory is false, are necessary truths and, therefore, true in every possible world.

5.4. Step 4 in the Argument: The Unsoundness of the Ontological Argument

The idea of what are now called ontological arguments for the existence of God was first arrived at by St. Anselm and set out in his Proslogion. Anselm (1078) held that the idea of God is, by definition, the idea of a being than which no greater can be conceived. Anselm then asked whether such a being could fail to exist, and he argued that that would be impossible, since if existence were not an attribute of a being than which no greater could be conceived, then such a being might not exist, but if that were so, then one could conceive of a greater being that, along with all of its other perfections, also had the property of necessary existence. Thus, Anselm (1094–1098) concluded, the idea of a necessary being that which no greater can be conceived who failed to exist is a contradiction, and therefore the existence of a being that which no greater can be conceived must be necessary.

In the last century, several writers have set out and defended ontological arguments for the existence of God, including Charles Hartshorne (1941, 1965), Alvin Plantinga (1974), Richard Campbell (1976), Kurt Gödel (1995), Daniel A. Dombrowski (2006), E. J. Lowe (2007), Kevin J. Harrelson (2009), Alvin Plantinga (1974), and Yujin Nagasawa (2017). An excellent overview and discussion of ontological arguments for the existence of God can be found in Graham Oppy, Joshua Rasmussen, and Joseph Schmid, “Ontological Arguments” in the Stanford Encyclopedia of Philosophy (Oppy Graham and Schmid 2024).

Is it necessary, then, to survey the different attempts that have been made to defend ontological arguments for the existence of God? The answer is that it is not, since there is a crucial objection that shows that no ontological argument for the existence of God can be sound.

To arrive at that objection, it will be helpful to consider one of the most famous defenses of the ontological argument, namely, that set out in Chapter 10, Section 7—A Victorious Modal Version, pp. 213–17, in Alvin Plantinga’s book The Nature of Necessity (Plantinga 1974). There, he offers two versions of this argument, the second and simpler version of which is as follows.

Let us say that unsurpassable greatness is equivalent to maximal excellence in every possible world. Then

(42) There is a possible world in which unsurpassable greatness is exemplified.

(43) The proposition a thing has unsurpassable greatness if and only if it has maximal excellence in every possible world is necessarily true.

(44) The proposition whatever has maximal excellence is omnipotent, omniscient, and morally perfect is necessarily true.

Now here we should notice the following interesting fact about properties. Some, like is a human person, are instantiated in some but not all worlds. On the other hand, however, there are such properties as is a person in every world. By the principle that what is necessary or impossible does not vary from world to world, this property cannot be instantiated in some worlds but not in others. Either it is instantiated in every world or it is not instantiated at all. Using the term ‘universal property’ in a way slightly different from the way we used it before, we might say that

+D₂ P is a universal property if and only if P is instantiated in every world or in no world.

But clearly this property possesses unsurpassable greatness is universal in this sense, for this property is equivalent to the property of having maximal excellence in every world; since the latter is universal, so is the former.

From 42 and 43, therefore, it follows that

(45) Possesses unsurpassable greatness is instantiated in every world.

But if so, it is instantiated in this world; hence there actually exists a being who is omnipotent, omniscient, and morally perfect and who exists and has these properties in every world.

What is one to say about this argument? Given the use of modal logic and the technical style of the argument, one might think that showing that Plantinga’s argument is wrong would be a very challenging task. In fact, that is not the case at all, since all that is needed to refute not only Plantinga’s argument, but any ontological argument for the existence of God that has ever been advanced, is a slightly beefed-up version of the objection to Anselm’s ontological argument for the existence of God set out by his contemporary Gaunilo. Thus, consider the following passage from Gaunilo’s (n.d.) response on behalf of the fool:

For example, they say there is in the ocean somewhere an island which, due to the difficulty (or rather the impossibility) of finding what does not actually exist, is called “the lost island.” And they say that this island has all manner of riches and delights, even more of them than the Isles of the Blest, and having no owner or inhabitant it is superior in the abundance of its riches to all other lands which are inhabited by men. If someone should tell me that such is the case, I will find it easy to understand what he says, since there is nothing difficult about it. But suppose he then adds, as if he were stating a logical consequence, “Well then, you can no longer doubt that this island more excellent than all other lands really exists somewhere, since you do not doubt that it is in your mind; and since it is more excellent to exist not only in the mind but in reality as well, this island must necessarily exist, because if it didn’t, any other island really existing would be more excellent than it, and thus that island now thought of by you as more excellent will not be such.” If, I say, someone tries to convince me through this argument that the island really exists and there should be no more doubt about it, I will either think he is joking or I will have a hard time deciding who is the bigger fool, me if I believe him or him if he thinks he has proved its existence without having first convinced me that this excellence is something undoubtedly existing in reality and not just something false or uncertain existing in my mind.

Gaunilo’s idea was clearly that if there is some form of argument that can be used to show that it is necessarily true that there is a perfect being, then that type of argument can be exactly paralleled to show that there are any number of other perfect things—such as a perfect island—that also necessarily exist. Consequently, there must be something wrong with that type of argument.

Now I haven’t surveyed what defenders of ontological arguments for the existence of God have said in response to Gaunilo’s argument. I would think, however, that one would somehow have to try to make hay out of the fact that the proposition that there is a perfect island has a relevantly different logical form than the proposition that there is an omnipotent, omniscient, and perfectly good deity, though I confess to being unable to see how that response would go.

Perhaps an advocate of an ontological argument for the existence of God would reply that while Gaunilo’s argument provides some reason for thinking that the form of argument in question is probably unsound, it doesn’t prove that that form of argument is unsound. Alternatively, the response could be that ontological arguments for the existence of God can take other forms than that of Anselm’s argument—as is shown, for example, by Plantinga’s very different argument set out above (Tooley 1981).

Such responses, however, involve two failures. The first is a failure to appreciate the power of Gaunilo’s idea of constructing arguments that parallel the form of a given type of ontological argument for the existence of God, whatever that form may be. The second is a failure to see that once the idea of parallel arguments is on the table, one can diverge from Gaunilo’s idea of a parallel argument that proves the existence of some fantastic thing, such as a perfect island, to a parallel argument whose conclusion is instead logically incompatible with the existence of God.

To illustrate this, let us consider again Plantinga’s argument. Unsurpassable greatness is defined in proposition (42) as “maximal excellence in every possible world”, while in proposition (44) it is stated that whatever has maximal excellence is omnipotent, omniscient, and morally perfect is not only true, but necessarily true. The term morally perfect, however, means morally perfectly good. The idea now is, first, that the property of being morally good belongs to a family of properties, another member of which is the property of being morally evil. Because those properties belong to the same family of properties, the replacement of the former concept by the latter concept wherever the former concept is present, either implicitly or explicitly, will result in an argument that parallels exactly the structure of Plantinga’s argument. One therefore has two arguments that either stand or fall together.

To transform Plantinga’s argument, we need to start with proposition (44) and work backward. First of all, then, the expression “morally perfect” in Plantinga’s proposition (44) means “morally perfectly good”. It will have to be replaced, then, by the expression “morally perfectly evil”.

Second, proposition (44) also connects up the concept of “maximal excellence” with the concepts of omnipotence, omniscience, and moral perfection, so the expression “moral excellence” will need to be replaced by a new expression for a being that is omnipotent and omniscient, but morally perfectly evil. So let us replace the expression “maximal excellence” with the expression “maximal evilness”. The result will then be

(44*) The proposition whatever has maximal evilness is omnipotent, omniscient, and morally perfectly evil is necessarily true.

Next, working backwards, there is Plantinga’s proposition

(43) The proposition a thing has unsurpassable greatness if and only if it has maximal excellence in every possible world is necessarily true.

Here we need to replace the expression “unsurpassable greatness”, so let us use the expression “unsurpassable evilness”. Making that replacement, along with replacing the expression “maximal excellence” with the expression “maximal evilness”, then gives one:

(43*) The proposition a thing has unsurpassable evilness if and only if it has maximal evilness in every possible world is necessarily true.

Finally, we need to alter Plantinga’s proposition

(42) There is a possible world in which unsurpassable greatness is exemplified.

Given the change made in proposition (43), the appropriate replacement here is

(42*) There is a possible world in which unsurpassable evilness is exemplified.

Finally, given Plantinga’s

D2 P is a universal property if and only if P is instantiated in every world or in no world. this, together with statements (42*) and (43*) then entails

(45*) Possesses unsurpassable evilness is instantiated in every world.

Proposition (45*) is incompatible with Plantinga’s proposition (45), however, so it cannot be the case that both propositions are true. Every statement in Plantinga’s argument, however, maps into the corresponding starred statement in the corresponding argument that I have set out, where the mapping involves simply replacing the concept of goodness by the concept of evilness. Since those two concepts belong to one and the same family of properties, it is impossible for Plantinga’s argument to be sound while the other argument is unsound. The conclusion, accordingly, is that both arguments must be unsound.

The conclusion, in short, is that Gaunilo, nearly a millennium ago, set philosophers on the right road when it comes to responding, not only to Anselm’s ontological argument, but to any ontological argument in support of the existence of God. If only Gaunilo, rather than focusing just on the idea of a perfect island, had also considered the idea of an omnipotent, omniscient, and perfectly evil deity, the philosophical world would have been spared the ongoing attempts by theists to find a way of resurrecting a hopeless type of argument. What is extraordinary, of course, is the failure of philosophers, over nearly a thousand years, both to realize the importance of Gaunilo’s response to Anselm’s argument and to see that a trivial tweaking of Anselm’s argument provides the recipe for sinking all ontological arguments for the existence of God. Such is what someone called the “tragicomedy” of philosophy!

5.5. Step 5 in the Argument: The Existence of Possible Worlds in Which God Does Not Exist

We have just seen that if any ontological argument for the existence of God were sound, which would entail that the existence of God is logically necessary, then a completely parallel argument would show that the existence of an omnipotent, omniscient, and perfectly evil being was also necessary, so that one would have a proof of a contradiction. It cannot follow, then, from the very concept of God that God is a necessarily existent being, nor that God exists in every possible world.

5.6. Step 6 in the Argument: Basic Ethical Truths Do Not Depend Upon the Existence of God

We are now at the final step in the argument. At step 3, we saw that if there are any moral truths, there must be basic moral truths that obtain in every possible world. In addition, we just saw at step 5 that there must be possible worlds in which God does not exist. It then follows that there must be possible worlds in which basic ethical propositions are true but where God does not exist. One therefore has the following results:

Grand Conclusion 1: If there are any moral truths, then there are moral truths that do not depend on the existence of God.

But Mackie’s error theory states that there are no moral truths. Consequently, one also has the fundamental conclusion for which I am arguing:

Grand Conclusion 2: Provided that Mackie’s error theory is false, then there are moral truths that do not depend on the existence of God, so that ethics without God is possible.

6. Philosophy of Religion and Its Relevance to the Question of Whether Ethics Without God Is Possible

Near the beginning of my essay, I said that in addition setting out an argument in support of the view—with a minor qualification—that ethics without God is possible, I would indicate why I think it is crucial to consider how philosophy of religion might bear upon the question initially posed, and thus why it is a mistake to address the question posed without considering how philosophy of religion might bear upon the question initially posed.

My discussion has two parts. The first part concerns the question of the existence of God, while the second part is concerned with alternative questions that should be considered along with the question that was posed.

6.1. The Non-Existence of God

First of all, are there any good arguments in support of the existence of God? Many arguments have certainly been advanced that are labeled arguments for the existence of God, including, among others, (1) arguments for the existence of a first cause, which are based on the unjustified ruling out of an infinite regress; (2) arguments that appeal the claimed appearance of design; (3) arguments that appeal to physics, such as the Big Bang theory of the origin of the universe, or the fine-tuning of fundamental physical constants; and (5) historical arguments that appeal to supposed miracles.

With the exception of the fine-tuning argument, all of these arguments have been shown to be unsound, and in the case of the fine-tuning argument, my late colleague and retired professor of physics, Victor Stenger, in the section “Fine-Tuned for You and Me” in his book Has Science Found God, summed up his conclusions as follows (Stenger 2003, pp. 155–6):

I have examined the distribution of stellar lifetimes for one hundred simulated universes in which the values of the four parameters were generated randomly from a range five orders of magnitude above to five orders of magnitude below their values in our universe, that is, over a range of ten orders of magnitude. While a few are low, most are high enough to allow time for stellar evolution and heavy element nucleosynthesis. Over half the universes have stars that live at least a billion years. Long stellar lifetime is not the only requirement for life, but it certainly is not an unusual property of universes.

I do not dispute that life as we know it would not exist if any one of several of the constants of physics were just slightly different. Additionally, I cannot prove that some other form of life is feasible with a different set of constants. But anyone who insists that our form of life is the only one conceivable is making a claim based on no evidence and no theory.

The crucial point, however, is that the fine-tuning argument, along with almost every other argument for the existence of God—the ontological argument for the existence of God being the only notable exception—suffers the defect that it provides no reason at all for thinking that the supposed being in question is morally good. It could just as well be a demonic deity, or a deity unconcerned about good and evil.

Moreover, once those alternatives are on the table, there are then evidential arguments from evil, including arguments of the type that were first put forward posthumously by David Hume (Hume 1779) in Part XI of his Dialogues Concerning Natural Religion:

There may four hypotheses be framed concerning the first causes of the universe: that they are endowed with perfect goodness, that they have perfect malice, that they are opposite and have both goodness and malice, that they have neither goodness nor malice. Mixed phenomena can never prove the two former unmixed principles. And the uniformity and steadiness of general laws seems to oppose the third. The fourth, therefore, seems by far the most probable (Hume 1779, p. 114).

Humean-style arguments have since been advanced by Paul Draper in, for example, his article “Pain and pleasure: An evidential problem for theists” and defended by him in several subsequent articles.

Then, in addition to Humean style arguments from evil, there are also evidential arguments from evil based on equiprobability principles needed for a theory of logical probability, a type of argument that I first set out in the debate volume, Knowledge of God (Tooley and Plantinga 2008, pp. 115–50), and then later in The Problem of Evil (Tooley 2019, pp. 50–72).

The+ most common strategy that theists have employed in response to evidential arguments is to ignore them. There have, however, been articles attempting to refute such evidential arguments from evil, but every such attempt that I have seen suffered from the same shortcoming, namely, a failure to recognize the equiprobability principles that any sound theory of logical probability must contain.

What explains this? The answer is that contemporary philosophy of religion can be described in the way that the acerbic Australian philosopher David Stove (1927–1994) described the Arts Faculty at the University of Sydney, namely, as “a disaster-area, and not of the merely passive kind, like a bombed building, or an area that has been flooded. It is the active kind, like a badly-leaking nuclear reactor, or an outbreak of foot-and-mouth disease in cattle.” (Stove 1986, p. 1)

How has this situation arisen? The person who can claim the most credit for this situation is clearly, I suggest, Alvin Plantinga, with the publication of his 1984 article “Advice to Christian Philosophers”, (Plantinga 1984), in which he said, for example:

So the Christian philosopher has his own topics and projects to think about; and when he thinks about the topics of current concern in the broader philosophical world, he will think about them in his own way, which may be a different way. He may have to reject certain currently fashionable assumptions about the philosophic enterprise-he may have to reject widely accepted assumptions as to what are the proper starting points and procedures for philosophical endeavor. And-and this is crucially important-the Christian philosopher has a perfect right to the point of view and pre-philosophical assumptions he brings to philosophic work; the fact that these are not widely shared outside the Christian or theistic community is interesting but fundamentally irrelevant.

(Plantinga 1984, p. 256)

The current state of what can be loosely referred to as “philosophy of religion” is thus that it has become dominated by Christian philosophers of religion who have happily followed Plantinga’s advice, which is in effect to bid farewell to Socrates’ remark that “the unexamined life is not worth living,” so that rather than seriously considering whether there is good reason to accept one’s Christian beliefs, and seriously examining the strongest objections to those beliefs, one instead takes those beliefs for granted, and use them as starting points in one’s “philosophizing”.

This situation has been well summed up by J. L. Schellenberg in his article “Philosophy of Religion: State of the Subject Report” (Schellenberg 2009). There he says, summing up his discussion.

I think the conjunction of points I have made here helps to explain why we have the situation we do—why philosophy of religion has experienced such a great resurgence, and why it has been one so centrally featuring conservative Christian theology. We can understand why this has happened. What I want now to identify—and here we have my second theme—is an often overlooked consequence of all this, which again necessitates a reference to theology.

This consequence is that a certain question becomes pressing: a question about the demarcation of philosophy from non-philosophy, in this case, about the demarcation of philosophy of religion from theology and from theological apologetics. And a possible result of thinking about this question is to my mind very interesting: what Plantinga and Co. are doing is not really philosophy at all, as I have mostly been assuming so far, but rather theology or theological apologetics, on behalf of the Christian community as they understand it, using the tools of philosophy (Schellenberg 2009, p. 100)

6.2. Questions Worth Thinking About Related to the Question Posed?

First of all, there is a general question concerning how religious beliefs are related to ethics. The idea of God lies at the center of the three great monotheistic religions—Judaism, Christianity, and Islam. In the case of several other religions, most notably Buddhism, Hinduism, Jainism, and Sikhism, however, what one has is not the idea of God, but, first, the idea of reincarnation, according to which a person’s essence or soul survives the destruction of one’s body, and one then lives again in another body. This idea of reincarnation does not in itself involve any ethical content, but in all four of the religions just mentioned, the idea of reincarnation is combined with the idea of a law of karma, according to which how desirable a particular incarnation is depends upon the moral character that one exhibited in one’s previous incarnation.

The upshot is that one also has the question, “Is ethics possible without reincarnation and the doctrine of the law of karma?”

Notice, moreover, that when those questions are considered together, that would seem to support negative answers to both questions, since if God exists and if reincarnation and the law of karma are the case, ethical values are built into the very nature of reality.

The second point is this. Most monotheists are not simply monotheists. There are Jewish monotheists, whose God is Yahweh, and whose sacred book is the Torah (The Torah 1962), which describes Yahweh’s interventions in human history. Then there are Christian monotheists, whose God is a triune deity—God the Father, God the Son, and God the Holy Spirit. Christians accept the revelations from God described in the Torah, but even more important are the revelations described in the New Testament. Finally, there is Islam, which embraces a non-triune deity, Allah, who revealed himself to his prophet Mohammed, to whom he transmitted, literally word for word, the Islamic holy book, the Quran.

All three religions give rise to questions that parallel the one addressed here. Thus, one could ask

(1)

Is ethics possible without Yahweh?

(2)

Is ethics possible without the triune Christ god?

(3)

Is ethics possible without Allah?

Some of the points and arguments that I made in response to the question of whether ethics is possible without God would also be relevant to the three questions just mentioned, but other points would also be relevant because of what appear to be evil actions performed by the deity in question. Thus, in the case of Judaism, one has in the first book in the Torah, in chapters 6 through 8, the story of Noah and the great flood, where all of the animals on the Earth that were not on Noah’s ark, and similarly all the men, women, children and babies that were not on the ark, were drowned in the flood. In addition, there are the many evils that are discussed and debated in the volume Divine Evil? The Moral Character of the God of Abraham, edited by Michael Bergmann, Michael J. Murray, and Michael C. Rea (Bergmann 2011). Then, in the case of Christianity, in addition to evils just mentioned attributed to the deity, there are the especially problematic doctrines of original sin, according to which all of mankind somehow inherits the guilt of an action performed by the first man, Adam, and, even more serious, the doctrine of hell, according to which all humans that are not save will suffer eternal torment after death. Finally, Islam, like Christianity, embraces the doctrine of eternal torment of nonbelievers after death.

In conclusion, then, there are several issues related to the one that has been the focus here that also seem eminently worth addressing.