In order to help us understand what he calls the Ideal or the Good, Plato uses several different analogies in his book The Republic. The one I’d like to discuss here has come to be known as “The Divided Line,” which appears at the end of Book 6, and I’ll have to ask you to bear with me if it takes a while to get to the point. Plato describes a four-part hierarchy of Reality, if you will, with things that are transitory and illusory at one end, and that which is permanent and true at the other. For example, reflections and shadows are illusory in the sense that they are dependent on a physical object to exist. We can see the sun reflected on the ocean, but if it goes behind a cloud the reflection goes also.
This is easy enough to appreciate in the material or visible world, but Plato puts forth an analogous relationship in what he calls the invisible or intelligible world. The physical world itself is just a reflection of more permanent “forms.” Individuals come and go, but the “form” of humanity lives on. Individual examples of beauty come and go—flowers live and die—but Beauty itself remains, if we are awake to it. These “mathematical” (from the Greek for “something learned”) forms themselves are derived from the ultimate Form; the Ideal or the Good. The ability to know the Ideal is the unique gift of the philosopher, the “lover of wisdom,” since it cannot be known by the ordinary mind, which, like the sunlight on the water, is a mere reflection of it.
This hierarchy looks something like this:
Forms–>mathematical forms—>physical objects—>reflections
I believe another good example of this hierarchy is the tree, which may be why it plays such a prominent role in many myths and religious stories. Let’s follow it back. Trees of course produce leaves and fruit in their season, which is transient, and then the leaves fall off and die. (And we get to rake them up or blow them around.) Their transience is one reason they are often used as an analogy for the human race. In Homer’s Iliad, Glaucus responds to a question about his lineage by saying,
Even as are the generations of leaves, such are those also of men. As for the leaves, the wind scattereth some upon the earth, but the forest, as it burgeons, putteth forth others when the season of spring is come; even so of men one generation springeth up and another passeth away. (Book 6: 147-9)
The branches and trunk of the tree remain and we know that they will produce more leaves next year. (There are of course the evergreens which don’t drop their needles, and which we value as symbols of life and hope “in the bleak mid-winter.”)
But trees also have their own “intelligible” world, which we cannot see, but which we know must be there for the tree to exist. The roots, which in a way mirror the branches, go deep and nourish the whole tree—without them the branches and the leaves couldn’t exist. But in this analogy we can see that the earth itself is the ultimate source of the tree. It is not part of the tree itself, but the tree is anchored in it and draws its nourishment from it.
Comparing the two analogies would look like this:
physical objects=branches and trunk
I think Plato is saying that this is how we stand in relation to the Ideal: the Ideal itself is eternal Beauty, Consciousness and Bliss; we are just transitory expressions of it. When we remember this connection we can be happy, but all human misery begins when we forget it, and take our transient selves, our leafhood if you will, to be real. Like the leaves, the tree itself will one day die, as will the roots, but the earth, like the Ideal, will continue, and take back everything unto itself.
We should then, at this time of year when the transitory has disappeared, remember our deep roots which do not, and the earth itself which cannot. There are many other names given to the earth in this hierarchy, and this season gives us the opportunity to go within and remember our reliance on it.
If you need further proof that this time of year is also beautiful, consider these words of Ralph Waldo Emerson from Nature:
The leafless trees become spires of flame in the sunset, with the blue east for their back-ground, and the stars of the dead calices of flowers, and every withered stem and stubble rimed with frost, contribute something to the mute music. … To the attentive eye, each moment of the year has its own beauty, and in the same field, it beholds, every hour, a picture which was never seen before, and which shall never be seen again.