Species Ancient & Modern

I seemed to have misplaced my copy of Natural Right and History, one of the three books that most shaped the beginning of my career as a scholar.  In case you are wondering, the other two were Aristotle’s Politics and Harry Jaffa’s Crisis of the House Divided.  I encountered all three in a course I took with Jeff Wallin at Arkansas State University, many moons ago.  At any rate, I am going from memory here and, dare I say, deploying my own examples.  No one should blame Strauss, Wallin, Jaffa, or Aristotle for my reflections. 

According to Leo Strauss, philosophy begins with the discovery of nature.  Prior to that discovery, human beings were well aware that different things had different ways.  Menstruation was the way of women and peeing on posts was the way of dogs, just as a life of military training was the way of Spartans and a life of wine was the way of Athenians. 

Nature was discovered when someone in ancient Asia Minor realized that there was a difference between the fact that some people burn their dead and some people don’t and the fact that fire always goes up whether you are among the one people or the other.  The ways of peoples are partly determined by convention.  We do it this way because we agree that this is the way it should be done.  Other peoples do it differently. 

On the other hand, no one dishes up grains of sand or puts their latrines in their kitchens.  These ways are determined not by convention but by nature.  The philosophers tried to understand nature‑the things that did not change from one political community to another and that were, apparently, the same everywhere and always.  When philosophy turned to examine politics, with Socrates, the task was to determine how the various regimes emerged from one common human nature. 

Strauss came back to me yesterday when I encountered the following passage from the great philosopher of biology: Ernst Mayr.  The passage is addressed to a certain position in the philosophy of biology concerning the concept of the species.  Darwin himself seemed to accept this position in his Origin of the Species.  It is called nominalism, the view that species concepts like horse or housefly are entirely conventional, arbitrary groupings that we make up as we go.  Mayr would have none of that.  From Towards a New Philosophy of Biology:

I have always thought that there is no more devastating refutation of the nominalistic claims than the fact that primitive natives in New Guinea, with a Stone Age culture, recognize as species exactly the same entities of nature as western taxonomists.  If species were something purely arbitrary, it would be totally improbable for representatives of two drastically different cultures to arrive at the identical species delimitations.  Although a few nominalists still survive, it is now almost unanimously agreed that there are real discontinuities in nature, delimiting different species.

It’s pretty obvious to common sense that a house cat and a housefly belong to different species; but what about a dog and a wolf?  Some of the former look very much like the latter and they can breed together.  What about a horse and a donkey?  They can have a mule as a child but cannot have grandchildren.  Things get much messier when you look at plants, let alone microorganisms.  Is it possible that our species concepts are merely convenient? 

Mayr offers us a reason to reject that idea.  If a stone age culture marks out the same species distinctions as modern western taxonomists, then those distinction are probably not cultural artifacts. 

What strikes me about Mayr’s proof is that it makes precisely the distinction that Strauss points out.  Species are ontologically real because they do not change from one set of conventions to another.  The various species that we all recognize are not conventional categories but natural categories. 

I have been writing a paper for the meeting of the International Political Science Association in Brisbane, Australia, next month.  My topic is Darwin and the Declaration of Independence.  One common criticism of Darwinian biology is that it is incompatible with the Declaration’s account of natural rights.  The latter states that “all men are created equal.”  The critics claim that Darwinian biology destroys the concept of species as natural kinds and so precludes the argument in the Declaration.  How can all me be created equal if there aren’t really any human beings, if the human species is a mere convenience, imposed on a smear of organisms differing from on another only in degree? 

I think I have shown, in the current draft of my paper, that Darwinian biology allows for species distinctions that are more than robust enough for the purposes of the Declaration.  What Mayr’s proof shows is that the species concept in modern biology can be defended on grounds that go back to the very origins of philosophy in ancient Greece.  I am content with that.