Evolution, moral realism, and conditional imperatives

Is it true that genocide is wrong? Most of us would respond in the affirmative, would think that the answer is obvious, and would regard anyone answering in the negative as a psychopath, best immediately locked up somewhere where he can’t hurt people. And yet, that kind of response implicitly assumes that there is a fact of the matter about moral pronouncements, that some statements in ethics are true or false. But by what standard?


Moral truths — if they exist — don’t appear to be on par with scientific truths, despite much nonsense that has been written about it in recent years (see here and here). If a scientist says that, for instance, the planet Saturn has rings, that statement is true if, and only if, it turns out that Saturn does, in fact, have rings. This is referred to in philosophy as the correspondence theory of truth: a statement is true if it corresponds (to the best of our knowledge) to what’s actually “out there.”


Moral truths are also not (quite) like mathematical truths. In mathematics the Pythagorean theorem, say, is “true” if it can be derived deductively from a small number of axioms. The reasoning that leads to its derivation has to be coherent, meaning that the theorem has to be logically entailed by the axioms, and not lead to or imply any contradiction. This is known as the coherence theory of truth.


I don’t mean to imply that there is a sharp distinction between science and mathematics, nor that individual applications may not rely on a combination of the two theories of truth (indeed, we’ll see one such application below), but the above is a basic sketch that will serve us well in this essay.


So if moral truths don’t follow either a correspondence or a coherent account, what are we left with? Enter error theory. According to the excellent Stanford Encyclopedia of Philosophy:
“Understanding the nature of an error theory is best done initially by example: It is the attitude that sensible people take toward phlogiston, that level headed people take toward astrology, that reasonable people take toward the Loch Ness monster, and that atheists take toward the existence of gods. An error theorist doesn’t believe in such things; she takes talk of such things to be a load of bunk. The moral error theorist doesn’t believe in such things as moral obligation, moral value, moral desert, moral virtue, and moral permission; she takes talk of such things to be bunk.”


The upshot is that if you (like the majority of people) believe that there are such things as moral truths, you are a moral realist, but you need to provide an account of where moral truths come from. If you reject the existence of moral truths (and error theorists are just one class of philosophers who do) then you are left with the task of explaining how come so many people are prone to this particular type of error.


This is why I was curious to read a recent paper by eminent philosopher of science Kim Sterelny and his University of Canberra colleague Ben Fraser, entitled “Evolution and moral realism,” and published in the British Journal for the Philosophy of Science. Here is a summary of their approach:


“We are moral apes, a difference between humans and our relatives that has received significant recent attention in the evolutionary literature. Evolutionary accounts of morality have often been recruited in support of error theory: moral language is truth-apt, but substantive moral claims are never true (or never warranted). We: (i) locate evolutionary error theory within the broader framework of the relationship between folk conceptions of a domain and our best scientific conception of that same domain; (ii) within that broader framework, argue that error theory and vindication are two ends of a continuum, and that in the light of our best science, many folk conceptual structures are neither hopelessly wrong nor fully vindicated; and (iii) argue that while there is no full vindication of morality, no seamless reduction of normative facts to natural facts, nevertheless one important strand in the evolutionary history of moral thinking does support reductive naturalism—moral facts are facts about cooperation, and the conditions and practices that support or undermine it. … True moral beliefs are a ‘fuel for success,’ a map by which we steer, flexibly, in a variety of social interactions.”


Let me unpack the above, and see where this leads us. The rather uncontroversial premise of Sterelny and Fraser’s paper is that our sense of right and wrong derives from an instinct that was probably favored by natural selection in order to improve our prosocial behavior, because the latter — in highly social species like ours — increases individual survival and reproduction, which are the only things natural selection “cares” about. Elements of prosocial behavior of this sort, which we would call moral if observed in humans, are indeed present in other species of primates.


But as Sterelny and Fraser point out, evolutionary accounts have largely being co-opted by error theorists: while moral language is what philosophers call “truth-apt” (i.e., it looks like it’s referring to truths), actual moral claims cannot be demonstrated to be true, since neither the correspondence nor the coherence theory seem to apply.


This has actually always sounded strange to me, for the following reason. A similar argument could be made that natural selection evolved our intelligence not in order for us to discover truths about the world (including scientific truths), but rather to figure out how to best our rivals within social groups. This is referred to as the Machiavellian theory of the origin of mind (but see here for one criticism), and it would lead us to conclude that even our scientific utterances are “truth-apt” and yet “never true or warranted.” One theologian, Alvin Plantinga, actually makes that argument against naturalism (as opposed to supernaturalism), ironically using evolutionary theory to conclude that either evolutionary science is untrustworthy or philosophical naturalism is wrong. I think Plantinga’s argument is bogus, though it would require a separate essay to show why (maybe at a later time). Still, it seems really weird to say that science (including evolutionary theory) doesn’t at least approximate truths about the universe, given how well its products work in practice. So error theorists shouldn’t be that quick to co-opt evolutionary theory on behalf of their position, or they risk falling into something like Plantinga’s dilemma.


Which lead us to the three points that constitute the heart of Sterelny and Fraser’s paper. They consider evolutionary error theory within a broader framework, the continuum between “folk” (i.e., everyday) and scientific understanding of things. Let’s clarify by means of an example not related to ethics: the phenomena of sunrise and sunset. The folk understanding in pre-scientific times was that, literally, the sun would rise above the horizon every morning, and set below it every evening. The sun was understood in a variety of ways, metaphysically, but usually as some kind of god or manifestation of the divine. The scientific account, of course, is that the sun isn’t doing any such thing, and in reality it is the earth that rotates on its axis, causing the illusion of sunset and sunrise. An evolutionary error theory would say that although sunrises and sunsets are illusions, in the sense that they are not a truthful description of what is going on, they are useful, since people can regulate their days accordingly. For everyday life, it simply doesn’t matter whether it is the sun that rises or sets, or the earth that rotates around its axis.
This is why Sterelny and Fraser say that according to this approach “many folk conceptual structures are neither hopelessly wrong nor fully vindicated.” But how is evolutionary morality cashed out, using this framework? On the one hand, there cannot be any simple reduction of moral truths to scientific facts. On the other hand, “moral facts are facts about cooperation, and the conditions and practices that support or undermine it.”


This is an interesting move, but I think it succeeds only in part. Sterenly and Fraser are ambitious here, as they want to ground a kind of moral realism, or quasi-realism, in evolutionary theory. Essentially, they are saying that moral truths follow the correspondence account outlined above, in that something is morally true just in case it fosters cooperation among human beings, and it is morally wrong if it doesn’t.


But this simply cannot be the full story. I think it is morally right (“true”) to cooperate with the entire human race in order to achieve a peaceful and prosperous world. Unfortunately, this is certainly not the sort of cooperation that natural selection has ever fostered. On the contrary, human evolution has been characterized by competition, not cooperation, among groups, with cooperation limited to each in-group. Indeed, it can be argued that the natural human trait of xenophobia (which I assume we would unequivocally label as morally wrong) has been adaptive for much of the history of Homo sapiens: if someone looks different from members of your in-group, he’s probably dangerous and you should be wary of him.


It is true that Sterelny and Fraser are careful, and are not committed to the simplistic notion that whatever behavior was favored by natural selection it is ipso facto morally good. But there are simply far too many discrepancies between what a theory of evolutionary morality would predict and what most people nowadays consider morally right or wrong for their approach to get us very far.


What then? Are the error theorists right after all? I don’t think so. I suggest that the sort of considerations articulated by Sterelny and Fraser provide a good account of how a natural moral instinct might have evolved: to favor in-group prosociality. But ethics since the invention of language, and especially since the invention of philosophy in different parts of the world between two and a half and three millennia ago, has been about using reason to precisely articulate and usually expand what counts as moral. Slavery, oppression of women, and xenophobia were initially considered morally acceptable, because they either enhanced or did not get in the way of the functioning of human groups. But today we think of all those notions as morally wrong, and for good reasons.


These reasons are the result of a combination of a basic prosocial human nature, an innate sense of the existence of right and wrong things, and of reason applied to the amelioration of the human condition. The first two components are the result of biological evolution, the latter of cultural evolution, which took over once we left the African savanna between 70,000 and 40,000 years ago, and especially after the agricultural revolution of 12,000 years ago. While the natural selective imperative is to survive in order to reproduce, the cultural imperative goes well beyond it: we want to flourish, to pursue projects, to acquire a certain degree of independence, and so forth. Biology simply cannot account for that.


What does, then? As philosopher Philippa Foot famously argued in her landmark 1972 paper, “Morality as a System of Hypothetical Imperatives,” moral truths are conditional truths. IF we wish to build a peaceful world THEN xenophobia is immoral. IF we wish to maximize every agent’s ability to flourish THEN the oppression of groups or individuals is immoral. And so forth.
This makes moral truths a combination of correspondence and coherence. The correspondence part derives from the notion that there are certain facts about the human condition that we can ascertain empirically. For instance that individuals flourish if they are accorded some rights, like the right to health care, or education. The coherence part comes from the fact that IF … THEN statements are a matter of logic, and so reasoning built on their bases is valid in some cases and invalid in others.


Another way to put it is this: if moral reasoning is reasoning about hypothetical imperatives, as Foot correctly, in my mind, argued, then the structure of that reasoning is a matter of logic (coherence) while the assumptions from which one begins any such reasoning are empirical in nature (correspondence). If human beings were radically different kinds of beings, our moral philosophy would look very different, or perhaps wouldn’t exist at all. Hence the relevance to ethics of the concept of human nature.


Some people may be unhappy with what they will conceive as a weakened sense of moral truths. They want categorical, not just hypothetical imperatives. They wish for universal, mind-independent moral truths. Too bad, there is no such thing. Others will deny the above account and embrace a relativist position in which morality is an entirely arbitrary human construct. While theoretically possible, I challenge anyone who adheres to such position to actually live by it. It’s not going to happen because it isn’t a good concept of morality for humanity. Foot-style categorical imperative offer us the best available option to navigate between the Scylla of strict moral realism and the Charybdis of strict moral anti-realism.