Plato

I learned from my living teachers‑Jeff Wallin, Harry Jaffa, Bill Allen, Bill Rood, and Harry Neumann, among others.  The most important thing they taught me was how to read.  That made it possible to learn from other teachers‑Plato, Xenophon, Aristotle, Machiavelli, Montesquieu, among others.  One of the reasons that I became enchanted with the biosocial sciences is that this branch of modern science deepened, enriched and confirmed all that I had learned from all of the above. 

Tonight, while reading about the early evolution of living organisms, I returned to thinking about Plato.  Unlike Aristotle, who has been largely recognized as the founder of biology, Plato is still usually regarded as a philosophical dead end.  Yes, his moral thought is interesting, but his metaphysics is a joke. 

I think that the dismissal of Plato is altogether wrong.  The argument about justice in the Republic presents for the first time the elements that make up the basis of modern sociobiology.  I won’t go into that here.  Instead I will focus on the most famous Platonic idea, the one that most responsible for his poor reputation.  I mean, of course, the theory of ideas. 

The textbook interpretation of the theory goes like this: Plato believed that there were ideas, or forms, laid up in heaven.  These ideas are perfect and eternal.  All visible objects are visible and comprehensible because they somehow “participate” in these ideas; that is to say, they are expressions of them.  That sounds pretty air-headed, and so it is usually dismissed as such. 

To so whether this judgment is just, we need to see how and why Plato (or Plato’s Socrates) developed this doctrine.  Consider the difference between a painter and a craftsman.  The painter looks at a three-dimensional object and produces a two-dimensional image.  The image may be altogether realistic; however, it is only the image of an image.  It shows us one perspective on the object but lacks the reality of the original. 

The craftsman, by contrast, looks at the object and produces another object that is real.  It is somehow connected to the original and yet it is another thing.  Philosophy and its offspring science cannot hope to reproduce all the objects that they are investigating; they can, however, attempt to gain the same understanding as the craftsman.  The philosopher wants to know not just what the object (a tree, justice, beauty, etc.) looks like but what it really is.  How do we understand the difference?

Consider what it is like to approach a tall tree from a distance.  At first, the tree looks very small.  You can cover it up by raising your hand.  So, the tree is smaller than your hand.  That is what your eyes are telling you.  Now walk towards the tree.  It grows in size as you approach it.  When you are near, it is very large and your hand can no longer conceal it.  The tree is much smaller than your hand.  That is what your eyes are now telling you.  Your eyes are confused, but your mind is not.  You recognize that the tree hasn’t really changed in size.  What has changed is your perspective.  From this, Plato’s Socrates concluded, we do not perceive actual objects with our eyes at all.  We perceive them with our minds.  This tree right here is not in fact visible to the eye. 

If we stipulate that individual, living, three-dimensional trees do in fact exist, then we have to agree with Plato.  We depend on extrasensory perception to be aware of them.  Now walk around the tree.  It looks different from each direction.  Yet these different images all are produced by a single object‑the one individual tree‑that is apprehended by the mind.  No one image is truer than another, yet all are true enough. 

Plato took a leap here.  If this is what happens when we perceive an individual tree, what happens when we recognize a second tree as in some sense the same thing?  Plato’s Socrates suggested that just as one individual tree exists behind the various images it casts as we approach it and walk around it, so the idea of the tree must exist behind all the individual trees that we encounter.  Just as our mind perceives the individual and so integrates our various images of it, so our mind perceives the idea of the tree and so allows us to recognize a general category.  Just as the individual tree changes in our perception of it, so trees come and go but the idea of tree remains the same. 

I say that Socrates “suggested” this because he is very careful in the dialogues.  He frequently says only that it is something like this.  He is also very uncertain as to what should be included in the realm of ideas.  Is it complex objects like trees or simpler concepts like mathematical forms?  There must be something more permanent and comprehensible than the objects we perceive if we can hope to understand anything.  Plato, of course, was right. 

Our ability to categorize species of plants and animals is imperfect.  That we can do it at all is possible because we can perceive something that is more enduring that the individual organisms.  We are perceiving, if only dimly, an object that extends across space and backward in time: the history of a species. 

I submit that biology is pregnant with Platonic forms.  Consider the difference between a jellyfish and a catfish.  The jellyfish has a top and a bottom, but not left and right or a back and front.  This is called radial symmetry.  A catfish has a top and a bottom, a back and a front, and a left and right.  These are Platonic forms. 

I am not sure whether the Platonic forms are laid up in heaven or not.  I am sure that these forms are real and preexist the creatures that participate in them.  You probably have to get bilaterians (creatures with a right and left) before you get mobile creatures and eyes.  There are only so many possible forms in organic design space. 

The first bilaterians probably crawled along dense, bacterial mats harvesting their food.  Eventually, some of them discovered that the decaying bodies of their kind were rich sources of the nutrients they sought.  Then some of them discovered that their living fellows were an even richer source.  This evolutionary trajectory, which made possible creatures such as ourselves, was the result of organized life exploring the avenues made possible by a Platonic design space.