Morality and Evolution

Some days ago, I stated that ethics is more flexible than many people suppose. One reason for this is the nature of the moral object. I tried to explain how this works in the last post; more detail is found in the comments there. A second reason is that human nature itself is less fixed than many people suppose. This follows from the theory of evolution.

This issue is related to a post by Alexander Pruss, where he raises the question of why immoral behavior is not necessary for human flourishing:

Andrea Dworkin argued that sexual intercourse between a man and a woman is always wrong because it involves a violation of the woman’s bodily integrity. She concluded that until recent advances in medical technology, it was impossible for humans to permissibly reproduce. The antinatalists, on the other hand, continue to hold that it is impossible for humans to permissible reproduce. Such views lead to an incredulous stare. It is very tempting to levy against them an argument like this:

1. Coital reproduction is necessary for the minimal flourishing of the human community under normal conditions.
2. Whatever is necessary for the minimal flourishing of the human community under normal conditions is sometimes permissible.
3. Coital reproduction is sometimes permissible.

The condition “under normal conditions” is needed for (2) to be plausible. We can, after all, easily imagine science-fictional scenarios where something immoral would need to be done to ensure the minimal flourishing of the human community.

Reproduction is not the only case where issues like this come up. For instance, the destruction of non-human organisms, say plants, seems necessary for our flourishing. And I suspect that under normal conditions the killing of non-human animals is necessary, too (if only as a side-effect of plowing fields, say). Taxation may be another interesting example.

I have heard it argued that (2) is in itself a basic moral principle, so that killing non-human animals as a side-effect of vegan farming is permissible because it is permissible to ensure minimal human flourishing. But that seems mistaken. Rather, while (2) is true, it is not a moral principle, but a consequence of a correlation between (a) fundamental facts about what moral duties there are actually are and (b) facts about what is actually needed for minimal human flourishing under normal conditions.

This leads to an interesting and I think somewhat underexplored question: Why are the moral facts and the facts about actual human needs so correlated as to make (2) true?

Theists have an elegant answer to this question: God had very strong moral reason to make humans in such a way that, at least normally, minimal flourishing of the community doesn’t require wrong action. Non-theists have other stories to tell. These stories, however, are likely to be piecemeal. For instance, one will give one evolutionary story about why we and our ecosystem evolved in such a way that eating persons wasn’t needed for our species’ survival, and another about why we evolved in such a way that morally non-degrading sex sufficed for reproduction. But a unified answer is to be preferred over piecemeal answers, especially when the unified answer is compatible with the piecemeal ones and capable of integrating them into a single story. We do, thus, get some evidence for theism here.

I tend to agree with Pruss here on a certain level. Thus I have argued myself that the fact that the world is good implies that its principle is good. However, his argument is more particular than that. He is claiming that principle (2) could have failed to be true empirically , and consequently that there was a need of some special effort to make sure that it did not fail to be true. He is presumably not rejecting the theory of evolution, but he is arguing that God needed to take special care to ensure that evolution did not follow certain paths where (2) would have ended up being false.

In contrast, I would argue that (2) could not possibly have failed to be true. This follows from an Aristotelian view of ethics and from the nature of moral obligation. Virtue simply means those habits that lead to human flourishing, and moral obligations are simply those things which are necessary for the human good. So it is evident that there was no need for any special measures to prevent immorality from being necessary for human flourishing. Whatever was necessary would have been moral.

Pruss gives examples: why isn’t eating persons necessary for survival, and why isn’t morally degrading sex necessary for reproduction? (In the comments he gives rape as an example of morally degrading sex.) As Pruss points out, a reasonable evolutionary account can be given for each thing of this kind. Generally speaking, prey populations must significantly outnumber predator populations for stability, and this implies that even if it is possible for some species to prey on itself to some extent, as in cannibalism, it is not likely to be necessary; most of the nourishment must come from elsewhere.

Similarly, given the nature of rationality, it would be highly unlikely for lack of consent to be necessary for a reproductive process between two individuals. One could imagine its necessity: perhaps reproduction only happens when hormones are present in the blood which are only emitted in circumstances of distress and unwillingness. But the fact that this might be possible in principle does not make it a likely thing to evolve; to the extent that a rational party is unwilling to reproduce, reproduction is unlikely to happen at all. So this kind of situation is likely to lead either to extinction, or to a new situation where lack of consent is no longer necessary.

Pruss’s response is that “a unified answer is to be preferred over piecemeal answers.” But this only works if it is in fact true that (2) would have been false if eating persons had been necessary for survival, or if lack of consent had been necessary for reproduction.

I would respond to Pruss in two ways. First, as I have already stated, (2) could not have been false, and would not have been false even in Pruss’s imaginary scenarios. Second, human life as it actually is has properties which directly suggest that no special effort has been taken to avoid such things. These two claims might seem inconsistent. I will explain their consistency when I come to the second point.

Regarding the first point, suppose eating persons were necessary for the survival of the human race. Let’s say that when someone reached the age of 15, it was necessary for him to eat an older person or die of a fatal disease. This would be part of the human growth process.

It is obvious, and Pruss concedes that it is true, that if this were the case, all humans would agree that it was morally acceptable for the 15 year old children to eat the older adults. This would presumably have some concrete social arrangement, perhaps with the very oldest being eaten. They might not like the fact, but even the ones being eaten would presumably accept the necessity of the situation, and in most cases consent to it. Pruss simply claims that despite the fact that all humans would agree that the behavior was moral, it would be objectively wrong.

This seems to me to deserve the “incredulous stare” that positions like Andrea Dworkin’s and the antinatalists’ receive. What could even be meant by the supposed objective wrongness in that situation? And if there is such a thing, perhaps many things that we do in everyday life are objectively wrong as well, and we simply don’t know it, in the same way those people would not.

Again, consider the idea that non-consensual sex might have been necessary for reproduction. This situation seems even more unlikely than the previous, for the reasons given above, but given that it were an actual situation, again, virtually all humans (possibly with exceptions like Andrea Dworkin) would agree that reproduction was moral. Lack of consent would no more make reproduction immoral, in that situation, than the fact that children do not consent to much of the treatment they receive from their parents means that raising children is immoral.

This point is in fact a good transition to my second claim. Human life requires that children receive a good deal of treatment to which they do not consent, and with which they often strongly disagree. There is nothing great about this situation, but it is inevitable. And this kind of point illustrates my claim that no special effort has been taken to avoid such situations. If eating people had been necessary for survival, or non-consensual sex had been necessary for reproduction, we might very well have recognized that these things were unfortunate necessities, but we would not have concluded that they were immoral, and in fact they would not have been immoral, given those circumstances.

We could find other examples of “unfortunate” situations in human life as it is:

1) Breastfeeding tends to space births by preventing conception. But there is some evidence that occasionally it can cause an abortion, or at least contribute to causing one. Alan McNeilly says regarding this point:

The foregoing discussion has made it clear that suckling is the key to the suppression of fertility. The variable return of ovarian activity is related to the variable pattern of suckling input and how fast the baby feeds. It is known that conception rates in women who are still breastfeeding but have resumed menstrual cycles are lower than those in women who have resumed menstruation after stopping contraception. The reason for this has now become clear. When ovulation occurs during lactation, it is often associated with reduced or inadequate corpus luteum function, resulting in reduced progesterone secretion [23-25]. The implication is that conception in a number of cycles can occur, but inadequate luteal function prevents continuation of the pregnancy.

Some people would argue that this definitely cannot happen, using an argument somewhat analogous to Pruss’s own argument that God makes sure to avoid such unfortunate situations. Thus someone says on the Catholic Answers forum,

You have to be careful about the crazy things that are put out there. Where did you read this?

Surely you’re not suggesting that breastfeeding is a sin?

Breastfeeding does NOT hinder implantation. It really wouldn’t make sense for G-d to give us the ability to lactate for which to feed our children while potentially destroying fertilized eggs by preventing their implantation

Naturally, nothing is settled by this argument. But the commenter here is right about one thing: we already know that breastfeeding is not immoral. And that fact is not going to change, not even if we discover that it frequently causes abortions.

2) The headship of the man in a family is arguably necessary for human flourishing, or at least was in the past, but the resulting subjection of the woman seems somewhat unfortunate, even though (by my own argument) not wicked. Even the book of Genesis suggests that something is not quite right there, by making it a consequence of original sin.

3) Religion and philosophy are arguably necessary for human flourishing. But it is difficult to know the truth about these matters, and humans tend to hold positions regarding them for social reasons. And if we suppose that we personally possess some part of the truth about these matters, it follows that most of those in the past were substantially mistaken about them, given the extent of human disagreement in such matters. This is not merely a question of lacking the good of truth. Rather, the fact that people do not naturally care much about that truth seems to be an unfortunate moral situation, much like the imaginary situations invented by Pruss.

Finally, we can consider one more imaginary situation. Suppose that the real world turned out to be like the world of Horton Hears a Who! Suppose that every time you took a step, hundreds of tiny rational creatures were killed. No normal human would lie down and die after discovering this fact. Pruss, I think, would assert that it would be the right thing to do, but he would be in a tiny minority. Most people would change nothing, and I would agree with them. I would respond that 1) the situation would not change the moral object of any human action, which would mean that anything we are justified in doing now, we would remain justified in doing; and 2) the population comparison involved implies a vastly higher economic value to normal human beings, which would imply that we would remain justified in living normal human lives even after considering the secondary consequences of our behavior.

The arguments of this post imply that in principle morality could have been somewhat different, depending on the details of how human life evolved. But the arguments imply not only that it could have been different, but that it remains changeable in some ways, because the process of evolution does not come to an end, since it is a necessary result of imperfect copies. Naturally, this kind of change should be expected to take place mainly over very long periods of time, but this will not necessarily prevent it from happening.