Day 2 & 3: Evolution & Ethics - They Come in Twos

January 21, 2010 Tags: Ethics Philosophy Science

It seems that often in the attempt to explain an idea, people will set up dualisms to more clearly define the terms and concepts in question. This two-sided approach seems to come up time and time again in the discussion of the origins of human morality — pitting moral reasoning against moral emotions, intellect vs. passion, nurture vs. nature, culture vs. genes, etc. I've been wondering about the usefulness of dividing controversial issues into these extreme dichotomies, especially when the subject matter seems either A) too complex to even formulate sides that are truly distinct, or B) more realistically involving a place somewhere in the middle. Granted, dualisms may be useful to illustrate a point — after all, it is helpful to define what something is by illustrating what it is not — but there is a tendency to paint caricatures instead of real positions.

This seemed to happen in the debate between Darwin and one of his critics, St. George Jackson Mivart. Mivart actually agreed with much of what Darwin had proposed in the Origin of Species and was a supporter of natural selection, but the two scientists had a falling out after Mivart wrote a scathing review of The Descent of Man. Their main point of disagreement was the difference between humans and other animals — particularly that difference which leads to morality. Whereas Darwin argued it was a difference in degree, Mivart was adamant that it was a difference in kind.

Mivart's argument goes like this: no one denies that man is an animal, but the mistake is to conclude that man is no more than an animal. There is plenty of evidence to show that we share with other primates the capacity for sensations, passions, desires, etc. But sensational knowledge of the world is fundamentally different from intellectual understanding. What sets humans apart is their intellectual faculty and ability to reflect upon their experiences. Morality, which is uniquely human, requires some sort of judgment to evaluate competing emotions and desires. And this ability to judge is not simply an outgrowth of the evolved capacity to feel emotion — it is another thing altogether. Darwin's mistake is getting so caught up in man's similarities to animals that he obscures the crucial dissimilarity: a moral sense that we do not share with any other creature.

In this argument we see the two sides shaping up quite nicely: Darwin's morality as a continuous evolving capacity that developed from lower animals to humans (it only differs in degree) vs Mivart's morality as an discontinuous jump (it differs fundamentally in kind). But was Darwin really advocating this definition of morality? Is there any room for him to accept some sort of difference in kind? There just may be. Reading through The Descent of Man, one finds seemingly contradictory statements about the human moral capacity that suggest Darwin may not have had the view Mivart charged him with. On the one hand, Darwin says that:
"...the mental faculties of man and the lower animals do not differ in kind, although immensely in degree. A difference in degree, however great, does not justify us in placing man in a distinct kingdom..."
That seems like a rather straightforward statement. But Darwin also acknowledges that:
"A moral being is one who is capable of reflecting on his past actions and their motives- of approving of some and disapproving of others; and the fact that man is the one being who certainly deserves this designation, is the greatest of all distinctions between him and the lower animals."
Even later he admits that articulate language is "peculiar to man." This sounds inconsistent, but only if we are using Mivart's two-sided notion of morality, one that pits "degree" against "kind". We could see Darwin as viewing the human moral sense as less of a radical break and more of an emergent property (this is an interpretation Larry Arnhart proposes in his book Darwinian Natural Right). If Darwin is describing a novel trait that appeared at a high level of complexity, producing an intellectual capacity that could not have been predicted at lower levels, then he is not contradicting himself. He really can say that man is distinct from other animals in a fundamental way (given the size and complexity of the human brain), without giving up the claim that man evolved his morality in a continuous way. This does not imply a break in the laws of nature, but rather an underlying uniqueness of human morality that depends on emergent traits. Novelty, therefore, can arise in a way that is compatible with Darwin's theory.

I'll most likely have more to say on the dualisms that reappear in this evolutionary story, but so far it seems like breaking out of a two-sided world can be quite helpful.