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.
