Dr William Large
Last week you were introduced to the first beginnings of Greek philosophy, and I tried to show how relevant this philosophy is to you, since your own present day world picture is to some extent a product of it. I tried to show you how the way the Presocratics thought about the world is much the same as ours, not only in the beginning of the development of scientific and rational thinking, but more importantly as the laying of the foundations of the fundamental language which we use to express our basic experience of the world; a language that I called metaphysics. I also put forward the claim that this view of the world, which is still today our world-view, is greatly different from the mythical and religious conception of the world that you find in the first verses of Genesis, for example, or the poems of Hesiod.
In the next two weeks, we shall look at two of perhaps the most important Presocratic philosophers, Heraclitus and Parmenides. They are important for us because they were significant influences on the thought of Plato, but also because they offer two very different versions of philosophy, which is still the main fault line within philosophy today.
Heraclitus was born in
One of these philosophers, who is the greatest source of our understanding of Heraclitus, is Plato himself, because he saw one of the main aims of his own philosophy was to defeat the scepticism that he believed was the inevitable consequence of Heraclitus’ way of thinking. Because Plato saw Heraclitus as his opponent, he tended to give only a one-sided view of his philosophy. But because this one-sided view is the way that Heraclitus has passed down into tradition, because of the fame and influence of Plato himself, it is worth, first of all, examining this interpretation.
At the heart of Plato's interpretation of Heraclitus is the fragments concerning the river, which some of you might have heard before, since it is the most famous of Heraclitus’ images.
For, according to Heraclitus, it is not possible to step into the same river, nor is it possible to touch a mortal substance twice in so far as its state is concerned.
Heraclitus says somewhere that all things are in movement and nothing stays put, and likening the real to the flowing of a river, he says that one could not step twice into the same river.
Now how does Plato, and those after him, who took his interpretation of Heraclitus to be right one, understand this image of the river? They understand Heraclitus to be saying that the world we see with our senses is constantly changing, like the river flowing past the onlooker. All the things that exist are coming into existence or going out of existence. To our uneducated person it might appear that existence is stable and permanent. I look at the chair in front of me and then I look at it again, and it still appears to me as the same chair. But this is an illusion, for even in that small period of time it has undergone imperceptible changes. And this is true not only for this individual chair, but for all existing things and for the universe itself in which these things exist. To use Aristotle’s example in the Physics, reality is like a rock being worn down by drops of water, although in the moment in which we are looking at the stone nothing appears to be changing, when we return months or even years later the rock has been hollowed out by the water. What appears stable on the surface to the uneducated human eye conceals continual change. The physical material world is neither stable nor permanent; it is the world of becoming and movement. It is another dialogue by Plato, the Symposium, where we can find have a excellent description of this unstable world of change:
Even during the period for which any living being is said to live and retain his identity - as a man, for example, is called the same man from boyhood to old age - he does not in fact retain the same attributes, although he is called the same person: he is always becoming a new being and undergoing a process of loss and reparation, which affects his hair, his flesh, his bones, his blood and his whole body. And not only his body, but his soul as well. No man's character, habits, opinions desires pleasures pains and fears remain always the same: new ones come into existence and old ones disappear.
This seems a plausible explanation of reality. So why would Plato believe that the consequences of holding it to be so dangerous to the ambitions of a rational account of the universe? Because, if this flux of change were the only possible description of existence, then knowledge would not be possible, since knowledge depends on permanence and stability. It appears that the necessary outcome of the doctrine of flux is scepticism. How would it be possible to define anything, if as soon as I called it a name, it changed into something else? A disciple of Heraclitus, Cratylus, took this doctrine so far as to assert that the only credible position would therefore be silence. How could one know something truly if it were always changing? Common sense would not have a problem here, since it lives in the world of change as though it were permanent and stable. But the knowledge of which Plato speaks, which according to him is the highest desire of the human soul, is scientific and philosophical knowledge. This knowledge can only be true knowledge if what it asserts is not merely true for one moment of reality, but for all time. Thus, he needs to show that Heraclitus’ description of a constantly changing physical universe cannot be the description of what reality is. He does this not by discounting that the physical universe is changing, which would be to return to the ignorance of the common man, but saying that knowledge is not dependent on this sensible reality of change, but another realm of existence altogether, which is the realm of the Forms or the Ideas, and which is, on the contrary, eternal and immutable. We shall examine this theory later in this course.
But has Plato given us the whole story of Heraclitus? I think not. He is only giving us one side. For although one side of Heraclitus’ philosophy is that everything is changing, the other side is that within this change there is unity and it is this speculative synthesis of diversity and identity, or order and chaos, as we would say in our modern jargon, which is entirely missing in Plato’s account. This speculative synthesis is Heraclitus’s doctrine of the logos (remember this word from the first lecture?). Unity within change and change within unity, this is the pattern or the law of the universe for Heraclitus. He wants to say that this pattern is not visible to everyone. ‘Nature’, he says ‘loves to conceal itself'’. It is for this reason too that Heraclitus writes so enigmatically and obscurely. Nature’s concealment means that it is not open to everyone to know its truth. Heraclitus writes, “Most people do not understand the things they meet with, nor do they know when they have learned, but they seem to themselves to do so.” Again it is a question of looking deeper into things than we normally do. First of all we need to go beyond the false stability of common-sense, and realise that beneath the apparent stability of things there is only becoming, but then we need to look even further, into the becoming as well and realise that all existent things in the world are this one and the same becoming which is constantly changing and this one and the same becoming is the universe.
The one mistake we can make here is to think that the difference between the one and becoming is a difference between two different levels of being, which would be precisely to read Heraclitus through Plato’s eyes. This would mean that becoming would be one level of being, corresponding to the physical world, and the unity of becoming would be another level of being, corresponding to the logos, to thought. But Heraclitus is not a dualist. He has no sense of a world down here, which would be finite and changeable and another world beyond this world, which would be eternal and immutable. As we shall see, this division between two worlds does not appear in Greek philosophy until Parmenides and is only consolidated as a world-picture by Plato (this kind of world-picture has, of course, important consequences for the development of Christianity). For Heraclitus there is only the one world: the one universe, the one cosmos which is at one and the same time changing and the same. One can imagine it as follows: from the perspective of separate things in the universe everything is in flux and in motion, but from a different perspective, from the perspective of the whole, which is the sum of all these different things, it is the same which changes, but even though it is changing, it still the one and the same. This is a very paradoxical and difficult thought, and Heraclitus does not make it any easier for us in the manner in which he describes it:
Things grasped together: things whole, things not whole; being brought together, being separated; consonant, dissonant. Out of all things one thing, out of one thing all things.
They do not understand how, while differing from it is in agreement with itself. There is a back turning connection, like that of a bow or a lyre. 
The one, the law, the
unity, the logos,
the sense, direction of the universe is not something external to it,
immanent. The logos and becoming are one and the same thing, looked at
different aspects. The one is not above becoming; it is becoming, just
becoming is not below the one, but is the one. There is a verse of
poem Tintern Abbey that seems to be
to capture a part of what Heraclitus obscurely communicates to us of
mysterious and mystical unity of all things:
And I have felt a presence that disturbs me with the joy of elevated thoughts;
a sense sublime of something far more deeply interfused,
whose dwelling is the light of setting suns, and the round ocean,
and the living air, and the blue sky, and the mind of man
a motion and a spirit, that impels all thinking things, all objects of
all thought and rolls through all things
 Fragment 91, from Heraclitus, ed. & trans. by T.M. Robinson, (Toronto: University of Toronto Press, 1987) p. 55.
 Cratylus 402a
Aristotle, Physics 253b9. Referred to by W.K.C. Guthrie, The Earlier Presocratics and the Pythagoreans, The History of Greek Philosophy, Vol. 1 (Cambridge: CUP, 1962), p. 451
 Symposium, 207d
 Cf., op. cit. Guthrie, p. 450
 op. cit. Heraclitus, Fragment 123, p. 71.
 op. cit. Heraclitus, Fragment 17
 ibid., fragment 10, p. 15.
 ibid. Fragment 51, p. 37.