Evolutionary skepticism

Post 572 Mar 9 JDN 2460744

In the last two posts I talked about ways that evolutionary theory could influence our understanding of morality, including the dangerous views of naive moral Darwinism as well as some more reasonable approaches; yet there are other senses of the phrase “morality evolves” that we haven’t considered. One of these is actually quite troubling; were it true, the entire project of morality would be in jeopardy. I’ll call it “evolutionary skepticism”; it says that yes, morality has evolved—and this is reason to doubt that morality is true. Richard Joyce, author of The Evolution of Morality, is of such a persuasion, and he makes a quite compelling case. Joyce’s central point is that evolution selects for fitness, not accuracy; we had reason to evolve in ways that would maximize the survival of our genes, not reasons to evolve in ways that would maximize the accuracy of our moral claims.

This is of course absolutely correct, and it is troubling precisely because we can all see that the two are not necessarily the same thing. It’s easy to imagine many ways that beliefs could evolve that had nothing to do with the accuracy of those beliefs.

But note that word: necessarily. Accuracy and fitness aren’t necessarily aligned—but it could still be that they are, in fact, aligned rather well. Yes, we can imagine ways a brain could evolve that would benefit its fitness without improving its accuracy; but is that actually what happened to our ancestors? Do we live on instinct, merely playing out by rote the lifestyles of our forebears, thinking and living the same way we have for hundreds of millennia?

Clearly not! Behold, you are reading a blog post! It was written on a laptop computer! While these facts may seem perfectly banal to you, they represent an unprecedented level of behavioral novelty, one achieved only by one animal species among millions, and even then only very recently. Human beings are incredibly flexible, incredibly creative, and incredibly intelligent. Yes, we evolved to be this way, of course we did; but so what? We are this way. We are capable of learning new things about the world, gaining in a few short centuries knowledge our forebears could never have imagined. Evolution does not always make animals into powerful epistemic engines—indeed, 99.99999\% of the time it does not—but once in awhile it does, and we are the result.

Natural selection is quite frugal; it tends to evolve things the easiest way. The way the world is laid out, it seems to be that the easiest way to evolve a brain that survives really well in a wide variety of ecological and social environments is to evolve a brain that is capable of learning to expand its own knowledge and understanding. After all, no other organism has ever been or is ever likely to be as evolutionarily fit as we are; we span the globe, cover a wide variety of ecological niches, and number in the billions and counting. We’ve even expanded beyond the planet Earth, something no other organism could even contemplate. We are successful because we are smart; is it really so hard to believe that we are smart because it made our ancestors successful?

Indeed, it must be this way, or we wouldn’t be able to make sense of the fact that our human brains, evolved for the African savannah a million years ago with minor tweaks since then, are capable of figuring out chess, calculus, writing, quantum mechanics, special relativity, television broadcasting, space travel, and for that matter Darwinian evolution and meta-ethics. None of these things could possibly have been adaptive in our ancestral ecology. They must be spandrels, fitness-neutral side-effects of evolved traits. And just like the original pendentives of San Marco that motivated Gould’s metaphor, what glorious spandrels they are!

Our genes made us better at gathering information and processing that information into correct beliefs, and calculus and quantum mechanics came along for the ride. Our greatest adaptation is to be adaptable; our niche is to need no niche, for we can carve our own.

This is not to abandon evolutionary psychology, for evolution does have a great deal to tell us about psychology. We do have instincts; preprocessing systems built into our sensory organs, innate emotions that motivate us to action, evolved heuristics that we use to respond quickly under pressure. Steven Pinker argues convincingly that language is an evolved instinct—and where would we be without language? Our instincts are essential for not only our survival, but indeed for our rationality.

Staring at a blinking cursor on the blank white page of a word processor, imagining the infinity of texts that could be written upon that page, you could be forgiven for thinking that you were looking at a blank slate. Yet in fact you are staring at the pinnacle of high technology, an extremely complex interlocking system of hardware and software with dozens of components and billions of subcomponents, all precision-engineered for maximum efficiency. The possibilities are endless not because the system is simple and impinged upon by its environment, but because it is complex, and capable of engaging with that environment in order to convert subtle differences in input into vast differences in output. If this is true of a word processor, how much more true it must be of an organism capable of designing and using word processors! It is the very instincts that seem to limit our rationality which have made that rationality possible in the first place. Witness the eternal wisdom of Immanuel Kant:

Misled by such a proof of the power of reason, the demand for the extension of knowledge recognises no limits. The light dove, cleaving the air in her free flight, and feeling its resistance, might imagine that its flight would be still easier in empty space.

The analogy is even stronger than he knew—for brains, like wings, are an evolutionary adaptation! (What would Kant have made of Darwin?) But because our instincts are so powerful, they are self-correcting; they allow us to do science.

Richard Joyce agrees that we are right to think our evolved brains are reasonably reliable when it comes to scientific facts. He has to, otherwise his whole argument would be incoherent. Joyce agrees that we evolved to think 2+2=4 precisely because 2+2=4, and we evolved to think space is 3-dimensional precisely because space is 3-dimensional. Indeed, he must agree that we evolved to think that we evolved because we evolved! Yet, for some reason Joyce thinks that this same line of reasoning doesn’t apply to ethics.

But why wouldn’t it? In fact, I think we have more reason to trust our evolved capacities in ethics than we do in other domains of science, because the subject matter of morality—human behavior and social dynamics—is something that we have been familiar with even all the way back to the savannah. If we evolved to think that theft and murder are bad, why would that happen? I submit it would happen precisely because theft and murder are Pareto-suboptimal unsustainable strategies—that is, precisely because theft and murder are bad. (Don’t worry if you don’t know what I mean by “Pareto-suboptimal” and “unsustainable strategy”; I’ll get to those in later posts.) Once you realize that “bad” is a concept that can ultimately be unpacked to naturalistic facts, all reason to think it is inaccessible to natural selection drops away; natural selection could well have chosen brains that didn’t like murder precisely because murder is bad. Indeed, because morality is ultimately scientific, part of how natural selection could evolve us to be more moral is by evolving us to be more scientific. We are more scientific than apes, and vastly more scientific than cockroaches; we are, indeed, the most scientific animal that has ever lived on Earth.

I do think that our evolved moral instincts are to some degree mistaken or incomplete; but I can make sense of this, in the same way I make sense of the fact that other evolved instincts don’t quite fit what we have discovered in other sciences. For instance, humans have an innate concept of linear momentum that doesn’t quite fit with what we’ve discovered in physics. We tend to presume that objects have an inherent tendency toward rest, though in fact they do not—this is because in our natural environment, friction makes most objects act as if they had such a tendency. Roll a rock along the ground, and it will eventually stop. Run a few miles, and eventually you’ll have to stop too. Most things in our everyday life really do behave as if they had an inherent tendency toward rest. It’s only once we realized that friction is itself a force, not present everywhere, that we came to see that linear momentum is conserved in the absence of external forces. (Throw a rock in space, and it will not ever stop. Nor will you, by Newton’s Third Law.) This casts no doubt upon our intuitions about rocks rolled along the ground, which do indeed behave exactly as our intuition predicts.

Similarly, our intuition that animals don’t deserve rights could well be an evolutionary consequence of the fact that we sometimes had to eat animals in order to survive, and so would do better not thinking about it too much; but now that we don’t need to do this anymore, we can reflect upon the deeper issues involved in eating meat. This is no reason to doubt our intuitions that parents should care for their children and murder is bad.

What’s fallacious about naturalism?

Jan 5 JDN 2460681

There is another line of attack against a scientific approach to morality, one which threatens all the more because it comes from fellow scientists. Even though they generally agree that morality is real and important, many scientists have suggested that morality is completely inaccessible to science. There are a few different ways that this claim can be articulated; the most common are Stephen Jay Gould’s concept of “non-overlapping magisteria” (NOMA), David Hume’s “is-ought problem”, and G.E. Moore’s “naturalistic fallacy”. As I will show, none of these pose serious threats to a scientific understanding of morality.

NOMA

Stephen Jay Gould, though a scientist, an agnostic, and a morally upright person, did not think that morality could be justified in scientific or naturalistic terms. He seemed convinced that moral truth could only be understood through religion, and indeed seemed to use the words “religion” and “morality” almost interchangeably:

The magisterium of science covers the empirical realm: what the Universe is made of (fact) and why does it work in this way (theory). The magisterium of religion extends over questions of ultimate meaning and moral value. These two magisteria do not overlap, nor do they encompass all inquiry (consider, for example, the magisterium of art and the meaning of beauty).

If we take Gould to be using a very circumscribed definition of “science” to just mean the so-called “natural sciences” like physics and chemistry, then the claim is trivial. Of course we cannot resolve moral questions about stem cell research entirely in terms of quantum physics or even entirely in terms of cellular biology; no one ever supposed that we could. Yes, it’s obvious that we need to understand the way people think and the way they interact in social structures. But that’s precisely what the fields of psychology, sociology, economics, and political science are designed to do. It would be like saying that quantum physics cannot by itself explain the evolution of life on Earth. This is surely true, but it’s hardly relevant.

Conversely, if we define science broadly to include all rational and empirical methods: physics, chemistry, geology, biology, psychology, sociology, astronomy, logic, mathematics, philosophy, history, archaeology, anthropology, economics, political science, and so on, then Gould’s claim would mean that there is no rational reason for thinking that rape and genocide are immoral.

And even if we suppose there is something wrong with using science to study morality, the alternative Gould offers us—religion—is far worse. As I’ve already shown in previous posts, religion is a very poor source of moral understanding. If morality is defined by religious tradition, then it is arbitrary and capricious, and real moral truth disintegrates.

Fortunately, we have no reason to think so. The entire history of ethical philosophy speaks against such notions, and had Immanuel Kant and John Stuart Mill alive been alive to read them, they would have scoffed at Gould’s claims. I suspect Peter Singer and Thomas Pogge would scoff similarly today. Religion doesn’t offer any deep insights into morality, and reason often does; NOMA is simply wrong.

What’s the problem with “ought” and “is”?

The next common objection to a scientific approach to morality is the remark, after David Hume, that “one cannot derive an ought from an is”; due to a conflation with a loosely-related argument that G.E. Moore made later, the attempt to derive moral statements from empirical facts has become called the “naturalistic fallacy” (this is clearly not what Moore intended; I will address Moore’s actual point in a later post). But in truth, I do not really see where the fallacy is meant to lie; there is little difference in principle between deriving “ought” from “is” than there is from deriving anything from anything else.

First, let’s put aside direct inferences from “X is true” to “X ought to be true”; these are obviously fallacious. If that’s all Hume was saying, then he is of course correct; but this does little to undermine any serious scientific theory of morality. You can’t infer from “there are genocides” to “there ought to be genocides”; nor can you infer from “there ought to be happy people” to “there are happy people”; but nor would I or any other scientist seek to do so. This is a strawman of naturalistic morality.

It’s true that some people do attempt to draw similar inferences, usually stated in a slightly different form—but these are not moral scientists, they are invariably laypeople with little understanding of the subject. Arguments based on the claim that “homosexuality is unnatural” (therefore wrong) or “violence is natural” (therefore right) are guilty of this sort of fallacy, but I’ve never heard any credible philosopher or scientist support such arguments. (And by the way, homosexuality is nearly as common among animals as violence.)

A subtler way of reasoning from “is” to “ought” that is still problematic is the common practice of surveying people about their moral attitudes and experimentally testing their moral behaviors, sometimes called experimental philosophy. I do think this kind of research is useful and relevant, but it doesn’t get us as far as some people seem to think. Even if we were to prove that 100% of humans who have ever lived believe that cannibalism is wrong, it does not follow that cannibalism is in fact wrong. It is indeed evidence that there is something wrong with cannibalism—perhaps it is maladaptive to the point of being evolutionarily unstable, or it is so obviously wrong that even the most morally-blind individuals can detect its wrongness. But this extra step of explanation is necessary; it simply doesn’t follow from the fact that “everyone believes X is wrong” that in fact “X is wrong”. (Before 1900 just about everyone quite reasonably believed that the passage of time is the same everywhere regardless of location, speed or gravity; Einstein proved everyone wrong.) Moral realism demands that we admit people can be mistaken about their moral beliefs, just as they can be mistaken about other beliefs.

But these are not the only way to infer from “is” to “ought”, and there are many ways to make such inferences that are in fact perfectly valid. For instance, I know at least two ways to validly prove moral claims from nonmoral claims. The first is by conjunctive addition: “2+2=4, therefore 2+2=4 or genocide is wrong”. The second is by contradictory explosion: “2+2=5, therefore genocide is wrong”. Both of these arguments are logically valid. Obviously they are also quite trivial; “genocide is wrong” could be replaced by any other conceivable proposition (even a contradiction!), leaving an equally valid argument. Still, we have validly derived a moral statement from nonmoral statements, while obeying the laws of logic.

Moreover, it is clearly rational to infer a certain kind of “ought” from statements that entirely involve facts. For instance, it is rational to reason, “If you are cold, you ought to close the window”. This is an instrumental “ought” (it says what it is useful to do, given the goals that you have), not a moral “ought” (which would say what goals you should have in the first place). Hence, this is not really inferring moral claims from non-moral claims, since the “ought” isn’t really a moral “ought” at all; if the ends are immoral the means will be immoral too. (It would be equally rational in this instrumental sense to say, “If you want to destroy the world, you ought to get control of the nuclear launch codes”.) In fact this kind of instrumental rationality—doing what accomplishes our goals—actually gets us quite far in defining moral norms for real human beings; but clearly it does not get us far enough.

Finally, and most importantly, epistemic normativity, which any rational being must accept, is itself an inference from “is” to “ought”; it involves inferences like “Is it raining, therefore you ought to believe it is raining.”

With these considerations in mind, we must carefully rephrase Hume’s remark, to something like this:

One cannot nontrivially with logical certainty derive moral statements from entirely nonmoral statements.

This is indeed correct; but here the word “moral” carries no weight and could be replaced by almost anything. One cannot nontrivially with logical certainty derive physical statements from entirely nonphysical statements, nor nontrivially with logical certainty derive statements about fish from statements that are entirely not about fish. For all X, one cannot nontrivially with logical certainty derive statements about X from statements entirely unrelated to X. This is an extremely general truth. We could very well make it a logical axiom. In fact, if we do so, we pretty much get relevance logic, which takes the idea of “nontrivial” proofs to the extreme of actually considering trivial proofs invalid. Most logicians don’t go so far—they say that “2+2=5, therefore genocide is wrong” is technically a valid argument—but everyone agrees that such arguments are pointless and silly. In any case the word “moral” carries no weight here; it is no harder to derive an “ought” from an “is” than it is to derive a “fish” from a “molecule”.

Moreover, the claim that nonmoral propositions can never validly influence moral propositions is clearly false; the argument “Killing is wrong, shooting someone will kill them, therefore shooting someone is wrong” is entirely valid, and the moral proposition “shooting someone is wrong” is derived in large part from the nonmoral proposition “shooting someone will kill them”. In fact, the entire Frege-Geach argument against expressivism hinges upon the fact that we all realize that moral propositions function logically the same way as nonmoral propositions, and can interact with nonmoral propositions in all the usual ways. Even expressivists usually do not deny this; they simply try to come up with ways of rescuing expressivism despite this observation.

There are also ways of validly deriving moral propositions from entirely nonmoral propositions, in an approximate or probabilistic fashion. “Genocide causes a great deal of suffering and death, and almost everyone who has ever lived has agreed that suffering and death are bad and that genocide is wrong, therefore genocide is probably wrong” is a reasonably sound probabilistic argument that infers a moral conclusion based on entirely nonmoral premises, though it lacks the certainty of a logical proof.

We could furthermore take as axiom some definition of moral concepts in terms of nonmoral concepts, and then derive consequences of this definition with logical certainty. “A morally right action maximizes pleasure and minimizes pain. Genocide fails to maximize pleasure or minimize pain. Therefore genocide is not morally right.” Obviously one is free to challenge the definition, but that’s true of many different types of philosophical arguments, not a specific problem in arguments about morality.

So what exactly was Hume trying to say? I’m really not sure. Maybe he has in mind the sort of naive arguments that infer from “unnatural” to “wrong”; if so, he’s surely correct, but the argument does little to undermine any serious naturalistic theories of morality.