If you are going to make a moral argument, whether in the seminar room or in the public square, people today expect you to avoid invoking God. Atheists and theists alike share this expectation, with atheists eager to show that their moral knowledge and action are uncompromised by disbelief in God’s existence, and theists eager to establish the rational credentials of their moral convictions and protect themselves against charges of fideism. This expectation is unwarranted, however, because God’s existence is directly relevant to moral knowledge and action: If appeals to God get ruled out, either by disbelief in His existence or reluctance to rely upon it, then it isn’t possible to demonstrate that there are moral absolutes.

Christopher Tollefsen’s recent argument in Public Discourse for moral absolutes flatters the expectations of today’s methodological atheism, because his argument purports to demonstrate on non-theological grounds that it is irrational ever to choose certain intrinsically bad actions. Although I agree with many of Tollefsen’s conclusions, and in particular his judgment that the WWII nuclear attacks were unjust, I think his argument is unsuccessful. Before addressing Tollefsen’s argument directly, however, I need to explain more precisely what aspect of moral knowledge depends upon knowledge of divine law, for a considerable portion of morality is demonstrable apart from knowing that God exists.

A moral absolute is an exceptionless norm against choosing a certain type of action that is intrinsically bad. Recognizing a moral absolute therefore involves two stages of evaluation: first, seeing that some act, such as killing an innocent person, is intrinsically evil, and second, seeing that one ought never to do evil. My contention is that a demonstration of this second stage of evaluation will need to appeal to God’s legislation against doing evil that good may come. This appeal of course assumes that God exists and that He legislates the moral law. Without this appeal, it remains logically possible for someone to think that there are intrinsically evil acts, and to think that virtuous people will habitually refuse to consider committing such acts, while yet refusing to infer that such acts must be avoided in every situation whatsoever.

It is instructive at this point to consider Aristotle. Aristotle thought that there were intrinsically bad actions that nobody ought to consider choosing, and although Aristotle was a theist, his conception of God was not as a providential creator or moral legislator. Aristotle’s example is noteworthy because it shows that it is possible to arrive at the conviction that intrinsically bad actions exist without appealing to God’s legislation. But Aristotle’s example is noteworthy also because of what he does not try to do, which is to demonstrate the truth of such absolute prohibitions by appealing to some more basic set of moral reasons. This is what Tollefsen mistakenly thinks he can provide, and on non-theological grounds. For Aristotle, however, the grounds for absolute prohibitions bottom out in the perception of actions as base and shameless. Such intuitionism is as far as I think non-theological ethics can go. Receiving the correct upbringing will get you to see that certain acts are intrinsically bad, and you ought never to choose them; but in order to go further and demonstrate why this is true, you need to be able to appeal to God’s legislation of the moral law, which is what proves the reasonableness of forbearing from evil in the extreme tight-corner situation.

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It is not a criticism of Aristotle to say that his belief in exceptionless moral norms bottomed out in intuition. This is true of most ordinary people for the entirety of their moral convictions, which is unproblematic unless you share the widespread but mistaken view that everyone needs to be a philosopher and have demonstrative knowledge of whatever he believes. Aristotle was unable to demonstrate the exceptionlessness of moral norms because he lacked a philosophically adequate conception of God as a providential creator. Tollefsen may ultimately think that God is a providential creator, but because this thought is idle in his defense of exceptionless norms, the argument falters. Let’s grant his assertions that there is a list of basic goods such as life, friendship, religion, work and play, aesthetic experience, etc., and that these basic goods comprise human well-being and are the ultimate reasons for doing whatever we do. From the fact that we must choose between pursuing mutually exclusive combinations of these various and distinct goods, Tollefsen says it follows that:

one should be always and entirely open to all the goods, in all persons, and never act directly or intentionally against any of the goods in any persons. “Openness” here should be understood to encompass the demand of the goods that they be promoted and protected: one is not open to basic aspects of human well-being if one always does nothing. The goods call, in various ways, for action on their behalf. But in all such action, the core negative requirement of morality is that one never intentionally act so as to damage or destroy an instance of a basic good.

The first thing to note about this argument is that, if it is correct, it generates too many exceptionless moral norms. If the basic good of life generates a concrete norm against intentionally killing people, then does the basic good of aesthetic experience generate an exceptionless norm against destroying artworks or interrupting the contemplation of paintings? This would be an absurd consequence that is at odds with the “common morality” that Tollefsen invokes. But if this consequence doesn’t follow, then the generation of exceptionless norms from the list of basic goods becomes obscure, and the theory of goods fails to provide any independent guidance for identifying or justifying exceptionless norms.

A second weakness in Tollefsen’s argument is the bald assertion that genuine tragic dilemma is impossible. Tollefsen needs to rule out the possibility of tragic dilemmas, because otherwise it would be impossible not to choose to act against some basic goods some of the time, so he asserts without argument that “one can always refrain from intentionally damaging instances of basic human goods.” Why should we think this is true? This assumption might be at home in Aristotle’s metaphysically harmonious universe of eternal species and natural purposes, or in Aquinas’s cosmology of divine governance, but Tollefsen is otiose to front-load his ethical theory with this sort of ontological presupposition. From the bare fact that we perceive life, religion, knowledge, and so on as basic values, it does not follow that these values will never conflict unavoidably in concrete cases.

To many people, the choice faced by the United States during World War II, between invading Japan or attacking it with nuclear weapons, appeared to be just such a tragic dilemma. The common morality of the Judeo-Christian tradition rejects the possibility of tragic dilemmas because it trusts in a providential God who ensures that we will not face them if we always avoid doing evil. Many philosophers and ordinary people outside of this tradition also reject tragic dilemmas because they perceive the world as a gift, or, like many naturalistic scientists, they simply assume that the world is ordered rationally without vagueness or contradiction. But if the aspiration is to produce a demonstrative argument, beyond simple perceptions or assumptions, then the only route is via philosophical theology.

It is possible to demonstrate that practices such as lying, killing the innocent, and adultery are generically bad and that everyone should avoid thinking of engaging in them. And it may be that, as Peter Geach has argued, “the rational recognition that a practice is generally undesirable and that it is best for people on the whole not to think of resorting to it is thus in fact a promulgation to a man of the Divine law forbidding the practice.” But if this sort of inference to morality’s divine source gets ruled out or postponed, then I don’t see any other avenue to justifying the exceptionlessness of absolute moral prohibitions. Domesticating God by placing Him in the anthropological category of “religion,” as one good among many, enervates the normative force of morality.

Truman’s goals in ordering the bombing of Nagasaki and Hiroshima were noble: to hasten the end of the war and to avoid the terrible casualties that were predicted as the result of an Allied invasion of Japan. The means he chose for the sake of these noble goals included the murder of civilian populations, however, which Tollefsen is right to condemn as unjust. To demonstrate why such injustice must never be considered, even in wartime emergency, requires a philosophical theology of a providential legislating God.