Because most philosophies that frown on reproduction don't survive.

Friday, June 16, 2006

Darwin vs. the Essentialists?

For those readers who share my undue interest in the intersection of evolution and philosophy, this post by John Wilkins from a few months back may be of interest. He surveys a number of other posts and tries to make the case that strict neo-scholastic essentialism was not in fact the prevailing view in biology prior to Darwin. Instead, he argues, it arose in response to Darwin's theory, and Ernst Mayr was primarily responsible for perpetuating the myth that essentialism had been the only real alternative and precursor to Darwinism.

Certainly, the 1840s-1860s were hardly a heyday of Aristotelian or Thomistic thought, and he's right that many 18th and 19th century philosophers and scientists subscribed to a loose typology in regards to species rather than a strict essentialism.

Still, I wonder if one of the reasons that essentialism has become one of the primary critiques of evolution (perhaps David or Shelray of Cosmos-Liturgy-Sex would know a bit more about this than I -- feel free to correct) is that essentialism touches on some very real truths that people intuitively recognize exist, and are not well explained by evolution or (more specifically) a basic materialist philosophical system ostensibly based upon it.

The evidence seems clear to me, though others differ, that the evolution of species does indeed take place. And yet, even if at a certain biological level a species is simply that population of creatures which currently possess a set of characteristics and can only breed successfully with one another, there's another sense in which the characteristics of those populations are significant -- at least if we are to make any sense of the world.

For instance, for the concept of medical science to make any sense, we must take it that certain things are 'healthy' and others 'unhealthy' -- and yet that suggests an inherent judgment as to how individuals within a given species ought to work.


John Farrell said...

Brendan, this is a great post--and great topic. Deep down, what bothers a lot of Catholics is the fact that in Darwin's theory, a species is never purely essential, meaning, its dynamic evolution implies that in a sense there really is no such thing as a 'species' in strictly essentialist terms.

Allan MacNeil has a provocatives post about this:

"This is not a trivial problem. Michael Ruse, in Darwin and Design: Does Evolution Have a Purpose?, asserts that one of the most important contributions of Darwin’s theory was that it put “design” back into nature (from which it had been removed by the “Newtonians”). To Ruse, “design” is essentially equivalent to “adaptation,” in that adaptations “solve” problems of biological function.

"But the problem here is one that Lewontin and Gould addressed almost 30 years ago in their landmark paper “The Spandrels of San Marco...”. Lewontin and Gould pointed out two things: (1) not all of the characteristics of living organisms are adaptations (i.e. some of them are the result of pure “chance,” not necessity), and (2) even the characteristics that are clearly adaptive don’t have to have arisen because they are adaptive, nor will they continue to exist for the same reason. They coined the term “exaptation” to refer to characteristics of organisms that are not necessarily adaptive, but which nonetheless are biologically significant.

"I would go much further than Lewontin and Gould: just as Darwin suggested (but did not come right out and say) that there are no such things as “species” (see "Origin of the Specious" in this blog), I believe that in nature there are no such things as “adaptations,” at least not insofar as such "adaptations" are "solutions" to biological "problems." That is, although there are characteristics of organisms that are correlated with relatively high reproductive success (and would therefore be considered by most evolutionary biologists to qualify as “adaptations”), it becomes problematic to decide exactly which of those characteristics are the “real” adaptations and which are merely “accidental.” "

Article here.

David said...

I suppose my comments would depend upon what definition of "essentialism" one takes; for example, there is the organized movement that focused on education, began just as WWII began, comprised a host of different philosophical view points, and shared only a vague notion of something along the lines of an essence or nature. In this case, I would say that one of these essentialists' position on common descent and whether one species can transition into another (it does not seem to me that the mechanism theory is important here) would depend upon his philosophical position. I do not think that all would necessarily reject the theory that one species can give rise to another.

However, it does not appear that we are talking about the organized education movement. Rather, I take it that we are taking about the less defined sense which begins with the classical philosophical view that all natural objects have an inherent essence that makes them what they are.

In this case, perhaps a short history of thought in terms of essence would be helpful. In fact, the idea of essence or nature actually gave birth to Western philosophy. Plato and Aristotle were convinced that the material world was intelligible and this intelligibility was gained by means of the essence or form of the entity.

Whether Platonist /neo-Platonist or Aristotelian this view was pretty much the standard view until William of Ockham in the 14th century. In what Ockham thought was protecting God's omniscience and omnipotence, he rejected the existence of universals (to be precise, he accepted what he called qualities [or essential accidents] as the only exception to singular existence). This is the beginning of the distorted thinking that gave rise to the philosophical materialism we have today.

Certainly there were materialists/ atomists from the days of Leucippus and Democritus, but it was William of Ockham, then Descartes and Bacon, followed by Hume, Laplace, Darwin etc. who provided the materialists with the theories they needed for materialist thought. But one needs to be clear here. The rejection of formal causality is a philosophical position unjustified by any evidence that modern science can bring to the issue.

Now before getting to the question as to why essentialists are the main critics of evolution, one ought to address Wilkins claim that biology had no essentialist view prior to Darwin as this bears on the answer. Wilkins ' claim seems to depend upon the following questions:

1. When did the science of biology begin?

If one allows that Aristotle inaugurated the science of biology then certainly the predominant view in biology was, whether Platonist or Aristotelian, that each species had a form/essence. However, after William of Ockham and with a growing philosophical materialism in the 19th century it is true that this view was in rapid decline within the academy.

2. By “essentialism” does one simply refer to the belief in essences or does one refer to the logical inference that because each biological entity has an essence/form there can be no transition of species? These are distinct and it is not at all clear to me that the belief in forms necessitates a rejection of common descent.

Here, I would say that until the theory of common descent arose about a century prior to Darwin, with the French zoologist Georges-Louis de Buffon, I do not see that the question would have come up as to whether one species could transition into another because each has its own essence.

I would say this. It is more likely that a Platonist would be this type of essentialist if one takes Aristotle's criticism as valid that there is no mechanism for interaction between the body and form. However, it is not clear that Aristotelian/Thomist philosophy could not support a transition from one species to another since the environment can and does have an impact on the form. However, the requisite material change that caused a transition of species would then seem to induce the introduction of a new form/species since the form itself cannot change from one substance to another.

O.k., now to the main question: why are essentialists the main critics of Darwinism? Given that precisions must be made and this is already too long a comment, I will answer why someone who believes in form/essence (even if he thinks that common descent is also a possibility) would be suspicious of Darwinism. It is exactly as you suspect, from Darwin himself as we now know from his dairies, to the propagandist Huxley, all the way up to present and what an eminent evolutionary microbiologist has termed the “carpetbaggers of evolution” Gould, Lewontin, and Dawkins, Darwin’s mechanisms have been used to push (implicitly and explicitly) a philosophical materialism. In fact, the random mutation theory implicitly confuses a physical mechanism with a philosophical claim that erroneously denies final causality. The distinction between a physically random (or stochastic) process and the illogical deduction that this means there is no Designer, is difficult for most to see.

Darwin said...


Sometimes I think one of the most appealing things to people about evolutionary theory is that it find the human trial-and-error method in nature -- or to flip it around, it suggests that our problem solving abilities are simply and individual application of a larger natural process. And yet, as this points out, if you take the 'no intent' gloss of evolution seriously, it's not really trial and error. It just happens, and none of it is an 'adaptation' or 'more fit' or any such thing. It just happens to be different and happens to survive.


I think you're right that Wilkins is using the term 'essentialist' pretty loosely, and that his usage leaves some questions open. I guess, it's a hard question to answer, in that no one had much of a reason to take a position on whether or not species were immutable prior to around 1800 -- so it's hard to say whether the prior understanding of such things was 'essentialist' or not, and if so what that meant.

Whatever it means, though, it seems to me that for the world to make any kind of sense we must allow for some degree of essence in relation to a species, even if that species is a moving target population undergoing sporadic genetic. Something I need to think more about in order to come up with any kind of reasonable statement. But I know there must be something there.