Error Theory Part 2 – Can Evolution Vindicate Morality?

In my previous post I described Error Theory and used Richard Joyce’s arguments to explain that our morality sense includes supernatural seeming notions such as the existence of a ‘moral equilibrium’ or ‘moral facts’ in the world that exist as inescapable demands by an outside authority.

This does not sit well with many a moral atheist, so several attempts to ‘explain morality’ via a naturalistic explanation have been attempted. The primary approach is to use biological evolution as a means of vindicating morality as naturalistic. Specifically, why can’t we use the fact that evolution produced morality as some sort of naturalistic vindication of our feelings of moralities objective rality and profound importance? This is the idea that Joyce now makes short work of.

Is Morality A System of Inference Like Logic?

One common argument in favor of the evolutionary vindication of morality is to ask the question of how the rules of logic are derived and accepted? A philosophical discussion about how to justify deductive logic is outside the bounds of this post. But the short form of such a discussion is that it is not actually possible to derive the rules of logic using the rules of logic themselves. We can intuitively see that the following is true:

  • If Sally is a woman then Sally is human
  • Sally is a woman
  • Therefore, Sally is human

We can even ‘codify’ the rules we use to derive such a conclusion. Specifically through what we call “modus ponens” we claim that given two premises:

  • P is true, and
  • If P then Q
  • That we are allowed to derive Q is true also.

But where does the rule “modus ponens” itself derive from? In fact, we do not derive it at all as it’s a postulate. It is ‘self-evidently true’ as it were.

What if there were an insane person to whom modus ponens were not self-evidently true? Would that then invalidate modus ponens? Of course not. So the suggestion has been made that a deductive rule like “modus ponens” is actually derived “from the ‘beliefs and practices’ of ‘rational man’” (p. 157)

Given this formula, it has been suggested that in a similar way we can “look to the beliefs and practices of moral people in order to derive propositions relating empirical facts and moral values that function not as premises in an argument, but rather as rules of inference…” (p. 157)

In fact, militant atheist Sam Harris has made precisely this argument. He has argued that the way we establish moral objectivity is that we look to an expert in morality like the Dalia Lama instead of Ted Bundy because the Dalia Lama is a moral expert whose opinion matters and Ted Bundy is not.

Joyce points out the problems with this argument. First of all, is it really true that we are derive modus ponens from observing rational people? Or is it perhaps not the other way around? That we observe that someone is rational if they accept modus ponens?

But even if we accept the premise that modus ponens is derived from rational people, how does that then imply that there is some sort of equivalent existing set of moral inference rules available? And who exactly gets to determine what those are? And why would we assume the Dalia Lama is such an inference expert and Ted Bundy is not save by use of our ability to infer from moral facts and rules? (Thus making Harris’ argument circular.)

Joyce points out how easy it is to get a “bunch of utilitarians to agree that an action’s maximizing happiness makes it morally obligatory…” or to get a “bunch of Kantians to agree that an action is prohibited if the universalization of its maxim cannot be willed as a law of nature.” But real the trick is to get those that haven’t already agreed to a particular moral view to agree to it in the first place. (p. 158) For all we know, maybe Ted Bundy’s morality is the correct moral rules we should be inferring by: do what you think is best for you for there is no evil or good.

One Ought to Be Good Because It’s Human Nature?

Another argument sometimes employed to suggest an evolutionary vindication of morality is as follows:

“…the evidence shows that evolution has, as a matter of fact, constructed human beings to act for the good of the community good; but to act for the community good is what we mean by being moral. Since, therefore, human beings are moral beings – an unavoidable condition produced by evolution – each ought to act for the community good.” (As quoted on p. 159)

Joyce challenges the idea that “to act for the community good is what we mean by being moral.” He easily points out that there are counter examples to this. He uses the thought experiment of a henchman of Ghenghis Khan deciding, and not unreasonably, that the best thing for his community is to wipe out all other communities they encounter, stealing their women.

Now Joyce does not doubt that our biological sense of morality did evolve to foster social cohesion and the survival benefits that come from that, but it does not follow that therefore that is what we mean by “morality.” On the contrary, we often mean by “morality” something that certainly does not benefit our community. (Think also of anti-slavers in pre-civil war Southern Community.)

Be that as it may, this is actually not the worst problem with the argument. In fact, even if we were to grant as a premise that all human beings do see “morality” is equivalent as “acting for the good of the community” the rest of the argument still does not follow. If evolution designed us to be moral (i.e. to act for the good of the community) then one would act for the good of the community and there would be no need to argue that one ought to as per an outside moral authority.

The simple truth is that we actually have multiple and conflicting desires. We want to cheat on our spouse and also don’t want to at the same time. And both desires are naturally part of human nature. Evolution included for us a natural moral sense, but also natural impulses and even (often sufficient) reasons to not follow it. Which is, of course, why we do not consistently act in moral ways and then simply rationalize why we were an exception afterwards.

Go back to the example, from the previous post, of a person that gets immense pleasure from killing people and makes that one of their chosen ends. (Not unlike Ted Bundy.) Even if we start with the assumption that evolutionary biology somehow allows us to claim that he “ought” not to kill because that is good for the community, why would we choose between two “oughts.” Which is now the correct evolutionary “ought”? That he “ought” to follow his innate moral human nature for the good of the community? Or that he “ought” to kill because that is one of his personal goals. And how do we adjudicate between these two equally valid oughts using only evolution as our guide? (p. 172)

Aristotle’s Argument – Fulfill Your Purpose

This brings us to the various sorts of Aristotelian arguments for morality, often still championed by modern scientists or philosophers. (Joyce uses the example of William Casebeer.)

Essentially, the argument is that we are to look at what separates one genus from another. What makes humans different from the animals, as it were? The Aristotelian claim is that humans have morality and can reason whereas other animals do not, therefore the ‘purpose’ of being human (its natural function) is to perform activities consistent with our teleological purpose. That is why we “ought” to be moral and reasonable. To Aristotle, a “good” thing is really an “exemplar” of its kind in that it fulfills its function well. So just as a “good hammer” is one that hammers well, so is a “good person” one that is moral and reasonable (amongst, perhaps, other things.)

Casebeer attempts to build an equivalent case based on evolution. Does not evolution build into our scientific world a case for such teleology? For example, does not a heart have the “purpose” of pumping blood or is not the “purpose” of an eye to see? And can’t we then extend that form of teleology into, say, a carpenter’s (or any person’s) purpose in society? Does this not then provide us with a basis for determining what is “good” based on fulfilling our purpose?

Joyce points out that the problem with this argument is that it makes a philosophical commitment to everything in reality having a goal or purpose even when the evidence seems to suggest otherwise. A thing having a goal or purpose happens at all because it exists in some sort of function-oriented context. The example of the ‘purpose’ of a heart, eye, or even a carpenter, works because they exist in such a function-context. For example, the reason evolution provides a ‘purpose’ for a heart is because of evolutionary theory itself – a community of single celled animals specialized to work interdependently, each fulfilling different functions (or purposes). A heart has evolved for a specific ‘purpose’ within the body. Likewise a ‘carpenter’ has a purpose within a society, but the society itself supplies the function-context for that purpose.

But is there an equivalent context for everything in the world? Is there such a context for ‘being human’? Aristotle attempted to form such a framework, coming up with teleological purposes for things that today we feel have no purpose at all, such as why there is rain in the winter. Aristotle’s physics shoehorned the world into such a teleological framework. But if we no longer accept Aristotle’s physics, Joyce asks if we can continue to simply make the logical leap that because a heart has a purpose and a carpenter has a purpose that therefore rain in the winter (or for that matter, “being human”) must also have a purpose? It would seem that such a leap is problematic. (p. 169-170) [1]

Looking A Bit Deeper – Evolution Undermines Aristotle’s Argument

There are two additional points of interest here that poses devastating problems for Casebeer’s Aristotelian argument. The first is that though evolution creates a function-context for a heart, it also insists that there is no particular reason why any current bodily purpose must continue to serve this purpose in the future. For example, feathers on a bird can’t, from an evolutionary stand point, have originally existed for flying. Evolutionists have found evidence that at first feathers were merely a way to stay warm, like hair or fur. Only later – long after feathers had evolved — were feathers co-opted for a new purpose: to fly.

So even when we do have a function-oriented context like evolution, the fact that a thing has a purpose still means basically nothing in determine what is good or bad in some metaphysical way.

Further, Casebeer’s arguments seem to confuse a person filling a role with the person himself. Does the fact that a Carpenter has a purpose in a society therefore imply that that carpenter must be a carpenter to fulfill his purpose and to be “good”? Or does it really just mean that it’s a bad idea for both carpenters and plumbers to do the same job and leave the other unfulfilled?

Teleology and Morality: Differing Definitions of the Word “Good”

Joyce also points out that there is an obvious difference here between what makes a hammer “good” and what makes a person “good.” For one thing, perhaps a hammer does have a specific purpose and maybe that purpose was never intended to be a doorstop. But it might work quite well enough for our purposes as a door stop. But the fact that it’s true function is going unfulfilled “matters not one whit. Why should evolutionary function be any different?” Joyce points out that the claim has been advanced that certain muscles exist for the purpose of throwing objects. Does that mean that you are doing something wrong if you choose not to throw things? (p. 172) So how can this argument then be turned into moral “oughts”?

Aristotle’s arguments are actually based on an equivocation of the word “good.” We have somewhat differ meanings of the word “good” in mind when we speak of a “good hammer” (i.e. one that fulfills its purpose well) and a “good person” (i.e. one that gives up his wants for the oughts of an outside moral authority.) Linking these two together can’t be done merely through the existence of a function-oriented context.

Does The Evolutionary Benefits of Morality Vindicate It?

Perhaps a better argument could be made to simply appealing to the fact that our biological sense of morality exists precisely because it gave survival advantage to our ancestors? This argument claims that the fact that we have a biological sense proves that morality benefits us, therefore, we should be moral. Therefore morality is objective and factual.

Now undoubtedly it is true that we have a moral sense because there was some sort of reproductive advantage to our ancestors. But Joyce points out that this argument fails because it’s redundant. If being moral is to our advantage today, then there is no need to appeal to the historical evolutionary advantage at all. One must merely appeal to the fact that being moral is to one’s own advantage and leave it at that. So this argument collapse to a simple utilitarian argument and faces the very same problems that any utilitarian argument does. (See the utilitarian discussion in previous post and also here.)

But if it is not to our advantage today to be moral, then how does an appeal to the historical evolutionary advantages of morality change our calculation now? [2] To use an equivalent example, there was an evolutionary advantage for our ancestors to eat high sugar foods because calories were scarce. That is why sugar and high fatty foods tastes so good to us. Does it then follow that today there is an evolutionary/reproductive advantage to eat lots of high sugary foods? And does the fact that it used to be an advantage (to the point where it got incorporated into our evolutionary biology) really in any way vindicate obesity? (And for the Aristotelians out there, does it then follow that this, being our nature, is therefore “good” by definition?)

The Evolutionary Debunking of Morality

Joyce himself takes the opposite approach to evolution and morality. He suggests that the fact that our sense of morality evolved does not vindicate it as factually real, but undermines it.

He asks: “Can we make sense of [our moral sense] having been useful for our ancestors to form beliefs concerning rightness or wrongness independently of the existence of [a really existing] rightness and wrongness?” Here he believes we can. (See arguments in previous post.)

Why couldn’t it be that it was an evolutionary advantage to have our brains feel that there is some sort of factual moral authority ‘out there in the world’ that we are ‘subject to’ regardless of our personal desires and that, if we violate that authority, a person (even ourselves) deserves some sort of punishment? In fact, we can make sense of such an argument regardless or whether or not any actual rightness or wrongness existed.

Joyce is careful to point out that this is not a self-defeating argument. We can’t take this argument and, say, apply it to math ability. Whereas our ability to perform correct math (or logic for that matter) is also a product of evolution, the only currently reasonable explanation for why we have math (or logic) abilities is that having correct math abilities somehow stemmed from the survival advantage of being able to solve such problems. There is not a serious explanation available for why it might have been a survival advantage for us to have evolved a false form of math, say a biological sense that 1 + 1 = 3. But we do have a plausible reason to believe that it might have been a biological advantage to have evolved a biological but factually false sense that there is such a thing as moral authority!

Therefore the idea that we can reasonably imagine evolution being the sole source of our biological sense (instead of having evolved because it was detecting actual moral facts about reality) does pose a serious challenge to the very existence of moral right and wrongness in the world.

Put more simply, we do not have to assume that there are actual moral facts about the world to be able to invoke an evolutionary explanation of the existence of our moral sense (which includes a belief about moral facts existing in the world and the existence of inescapable moral authority). So it may well be that our sense of morality is indeed an illusion, though one that was (and is) helpful to us.

Indeed, Joyce claims that (as arguments in the previous and current post demonstrates) that there are no arguments at all so far that can justify our moral judgments epistemically, though it’s easy to justify them instrumentally. So Joyce feels that morality is what we might call a useful illusion.


[1] It would seem that such a leap is problematic. This is also an example of how it is not true that the debunking of Aristotle’s physics left his metaphysics unscathed. The two were profoundly linked and can’t be so easily separated.

[2] Joyce also points out that if our morality really derived from evolution, then the study of evolution should be able to uncover or require changes to our moral rules. For example, we might find that the real reason we have a moral sense was to make us better at creating cohesive tribes that were then better as fighting wars. Therefore, having discovered this, war would then be morally justified. (p. 172 and 176)

2 thoughts on “Error Theory Part 2 – Can Evolution Vindicate Morality?

  1. It’s easy for evolutionary scientists to come up with convincing theories about the origin of various body parts, structure, and function. These make sense to me. But when it comes to human behavior, the arguments become so incredibly strained. How could evolution have endowed us with this “useful illusion?” I admire Joyce’s rigorous study of how utilitarian or Aristotelian theories on morality fail to explain it’s existence. But it seems so obvious from these arguments that the most rational explanation for the existence of morality must necessarily come from some kind of foreign interference in the evolutionary chain. If my wife and I suddenly had a baby with superhero powers, we wouldn’t look for explanations in our evolutionary genealogy, we’d look for kryptonite. And humans are the superheros of the animal kingdom.

  2. Its kind of funny. I bought Joyce’s two books almost a year ago and had just started reading them when I, for largely unrelated reasons, traded in my rational/scientistic worldview for the neo-pragmatism I adhere to now. Once I made made the change, I simply couldn’t stomach reading books like Joyce’s anymore without wanting to rip out every other page and burn it.

    More to the point, once one accepts that logic, evidence, etc. are themselves moral rules, then we have no independent reason to expect them to always win out when pitted against other moral rules such as murder, etc.

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