1 The Allegory of the Cave: Plato, Republic*
Though the systematic study of metaphysics was inaugurated by Aristotle, metaphysical theorizing did not begin with him. A variety of different theories about the ultimate nature of the world had been developed by those earlier Greek philosophers known as the ‘Presocratics’; Aristotle’s own teacher, Plato, was famous for his theory of Forms, an account of a realm of abstract reality to be apprehended by the intellect – a realm ‘above and beyond’ the ordinary world of particular objects that we perceive by the senses. Plato’s metaphysics is intimately linked to his theory of knowledge (see Part I, introduction to extract 2, above); he believed that in order to attain genuine knowledge we need to go beyond the changing world of day-to-day particulars and grasp the timeless and unchanging universals of which ordinary objects are imperfect instances (thus, a particular beautiful object is only beautiful in a limited and passing way – a mere copy of the Form of Beauty, the ‘beautiful itself’).
In our first extract, from the Republic (written in the early fourth century BC), Plato compares the noblest Form, the Form of the Good, to the sun: just as the sun makes ordinary objects visible, so the Form of the Good is the source of the intelligibility and reality of the Forms. Next, in the simile of the ‘Divided Line’, Plato suggests that ordinary everyday objects stand in the same relationship to the Forms as shadows do to their originals. And finally, in his famous allegory of the Cave, Plato compares the gradual ascent of the mind towards the Forms with a journey from darkness to light.
Within the cave (the ordinary world of the five senses), most of us are like chained prisoners watching shadows thrown by a fire. We adopt our opinions second-hand, manipulated and controlled by others. But even if we get free and look around the cave for ourselves, we are still only operating within the ordinary visible world, the world of particular objects. We need to struggle upwards, out of the cave, into the higher world of universals, grasped not by the senses but by the intellect. Our eyes dazzled by the brightness, we first can look only at reflections in pools (perhaps corresponding to mathematical objects, which help the mind to move away from particulars and towards abstract universals); but eventually we will be able to turn our eyes to the light of the stars and finally the Sun itself. The heavenly bodies here stand for the Forms, and the Sun represents the ultimate source of truth, the Form of the Good. In the upper world of Plato’s parable, we are not dealing with ordinary visible light; illumination comes instead at an intellectual level, from the supreme Form which ‘is the controlling source of all reality and understanding’. As always, Plato presents his argument in dialogue form: Socrates (representing Plato’s own views) speaks first; the respondent is Glaucon.
Let me remind you of what I have mentioned in the course of this discussion, and at many other times.
What?
The old story, that there are many beautiful and many good things, and so of all the other things which we describe and define – to all of them the term ‘many’ is applied.
True, he said.
And there is an absolute beauty and an absolute good, and of other things to which the term ‘many’ is applied there is an absolute; for they can be brought under a single idea which is called the essence of each.
Very true.
The many, as we say, are seen but not known, and the ideas are known but not seen.
Exactly.
And what is the organ with which we see the visible things?
The sight, he said.
And with the hearing, I said, we hear, and with the other senses perceive the other objects of sense?
True.
But have you remarked that sight is by far the most costly and complex piece of workmanship which the artificer of the senses ever contrived?
No, I never have, he said.
Then reflect: has the ear or voice need of any third or additional nature in order that the one may be able to hear and the other to be heard?
Nothing of the sort.
No, indeed, I replied; and the same is true of most, if not all, the other senses – you would not say that any of them requires such an addition?
Certainly not.
But you see that without the addition of some other nature there is no seeing or being seen?
How do you mean?
Sight being, as I conceive, in the eyes, and he who has eyes wanting to see; colour being also present in them, still unless there be a third nature specially adapted to the purpose, the owner of the eyes will see nothing and the colours will be invisible.
Of what nature are you speaking?
Of that which you term light, I replied.
True, he said.
Noble, then, is the bond which links together sight and visibility, and great beyond other bonds by no small difference of nature; for light is their bond, and light is no ignoble thing.
Nay, he said, the reverse of ignoble.
And which, I said, of the gods in heaven would you say was the lord of this element? Whose is that light which makes the eye to see perfectly and the visible to appear?
You mean the sun, as you and all mankind say.
May not the relation of sight to this deity be described as follows?
How?
Neither sight nor the eye in which sight resides is the sun?
No.
Yet of all the organs of sense the eye is the most like the sun?
By far the most like.
And the power which the eye possesses is a sort of effluence which is dispensed from the sun?
Exactly.
Then the sun is not sight, but the author of sight who is recognized by sight?
True, he said.
And this is he whom I call the child of the good, whom the good begat in his own likeness, to be in the visible world, in relation to sight and the things of sight, what the good is in the intellectual world in relation to mind and the things of mind?
Will