ParmenidesDr William Large
Following from last week we can say that Heraclitus’s world-picture, his cosmology, is very different from Parmenides’s. In fact, Parmenides saw his own philosophy as critique of Heraclitus’s view of the cosmos, and the whole Greek tradition which divided our understanding of nature into a surface and deep one, where the surface understanding applied to the knowledge of the senses, and the deep understanding to some a ‘vision’ that was hidden from most ordinary people. into surface and depth, where the surface was to be explained by a hidden principle or arche, and he did this not by arguing from the senses but from logic. It has been said that he was the first to introduce deductive arguments into philosophy. He wants to say that the whole approach of Heraclitus of divided being into the true and the false, or the one and the many, or even being and not-being, did not make any logical sense at all. This is not just because Heraclitus ended up saying paradoxical things, for even he realised that he did that, but that his whole method right from the very start was impossible.
Before we go into Parmenides’s doctrine, let me say a few words about the style of his work. The work is a poem and is written in hexameters, which is the same metre which Homer and Hesiod used. It might appear strange to us to present a philosophical doctrine in poetry, but for the Greeks poetry was not seen as literature as it is by us, but a mode in which one expressed the deepest truths about the cosmos. Also the poet was seen as having, because he was inspired by the gods, to have a deeper knowledge of existence than ordinary people. It seems, when we read the beginning of the poem that Parmenides himself really believed this. The poem begins with a fanciful story of him being taken by a chariot through the heavens to meet the goddess of justice, who is then supposed to tell him of the one true doctrines called the path of truth. However, I do not think we need to take it for granted that he actually thought this happened. Parmenides wrote this way because this is what his audience were used to hearing. What is important in this prologue is the gulf Parmenides paints between the world of ordinary knowledge and common sense, on the on hand, and the world of philosophy and truth, on the other. This is the division between knowledge gained through the senses, and that gained through reason. Even though Parmenides’s conclusion runs counter to common sense beliefs about reality, it is up to us to refute them logically, and if we cannot then we must accept their evidence as against the evidence of the senses. In other words, even though Parmenides presents the Way of Truth through the mouth of the Goddess, we should not confuse it with divine revelation. It is presented through rigorous deductive reasoning that we need to think through ourselves and not as an instantaneous miraculous insight given as a gift from a higher divine power.
This priority of reason over the senses is very important, as we shall see, in Plato’s own thought, if not to the entirety of Greek philosophy after Parmenides. To emphasise this gulf, he presents us with this story of leaving the mundane world for the sake of the divine. After the prologue, the poem itself is divided into two parts, the way of truth, which is Parmenides own philosophy, and the way of opinion, which is a fanciful mimicry of the usual pre-Socratic arguments for a principle or arche as the origin of the sensible universe. It is important to realise that the way of truth is to show that the way of opinion, which most people associated with true philosophy, is in fact absurd and nonsensical.
As I have already said, the traditional way of arguing in pre-Socratic thought is from the senses, and this is even the case with Heraclitus. I look at the natural world around me, and from the nature of the world, I postulate some origin or principle which makes sense of this natural world. In more formal language, we can say that the pre-Socratics argue from effects to an single hypothetical cause, like Thales’ water. What is important about Parmenides is that he does not argue from the senses, but from logic. Thus, in his argument with Heraclitus, if we suppose that he is writing with him in mind, is not that Parmenides himself believes he has a better explanation of nature, rather that any explanation of nature whatsoever, which takes the illogical form of Heraclitus’s type of natural explanation, makes no sense. We can decide whether this case or not simply by using are own minds without ever having to observe nature at all.
What then does the way of truth tell us about what truth is? The answer seems very simple, but as we shall see it has important consequences. “It is and it is not possible for it not to be”. The way of opinion, on the other hand, is said to be, “It is not and it is necessary for it not to be.” How can we explain this two very obscure mantras with respect to argument for nature or the universe having an arche and that this way of thinking is illogical? How does talking about being and not being, being necessary or not necessary, in relation to nature and principles, such as Thales’ water or the unity of opposites in Heraclitus, constitute some kind of refutation?
The way to begin to understand these two ways is see that the first way is the path of logical thought and the second way a path of thought which does not follow the rules of logic, like Heraclitus’ for example, but still believes that it is giving an adequate logos of the universe. What leads people astray is the use of their senses. This is because Parmenides believes, like all the other philosophers before him, that the senses cannot be trusted, but why doesn’t this lead him to positing an arche which would be the truth meaning of the senses like these other philosophers? It is because someone who does this is led to the contradiction of asserting that being and not being are both the same and not the same. How is this the case? Change for Parmenides is not seen as something which needs explanation, but a concept which is fundamentally illogical. If the relation between a subject and predicate is a real one, and I identify being with the subject, then the predicate, if it differs from the subject, must be non-being, but if that is the case, then something is and is not at the same time, and this does not make sense.  Likewise with change, if something changes, then I am saying that it both is and is not at the same time. I am saying that the subject is, but by identifying it with its predicates, which it cannot be, then I also at the same time identifying it with what it is not.
Parmenides’s argument with the very idea of an arche is that one cannot look for an underlying principle for that which cannot be explained logically, namely change. But the argument is also pushed one stage further. Let us say that arche is the fundamental reality of appearances, then the arche would be what is and appearances what is not. But if the arche is reality, then it does not make sense to say that the appearances are the reality also, which is what the arche is meant to explain. As soon as there is a distinction between reality and appearance, then it makes no sense to explain the latter by the former, for in reality, what your are positing are two realities one that is and one that is not, but reality cannot both be and not be and the same time. Thus there can only be one reality, which is being and being is thought. The world of the senses is not, and what is not cannot be.
This argument from reason demonstrates that if one is to have a true conception of being then it cannot be natural one. Being cannot have the property of sensible being, otherwise we end up with the aporias of change, which is the second path that asserts that being is what is not, and which is the logical absurdity that being is not being, or being both is and is not at the same time. On the contrary being must be identical with being, which is the first path, being is what is. If this is case, then being cannot be changing, but must be eternal and immutable, otherwise we would fall back into the same mistake of saying that being both is and is not. What is cannot come into existence out of what is not since what is not cannot give rise to something, since what is not cannot be intelligently spoken or thought of. If it did come into existence out of what is not, then it came into existence at a certain time. There is, however, no necessity that it comes into existence at one time, rather than any other, since this would mean that what is not, nothing, would have attributes that would determine ‘what is’ to be at this or that time, but ‘what is not’ cannot have any attributes since it is nothing. Since there is no reason for what is to come existence at one time or any other, and it cannot come into existence at all times, there is no reason to suppose that it came into existence at all – What is not cannot be the cause of something.
The Presocratic notion of an arche is that it is different from what it explains, that there is split between appearance and reality within reality. Parmenides’s argument is that it makes no sense to say that reality is both reality and appearance at the same time. Rather we must make a absolute distinction between reality, which is being itself, and appearance which is not being. This being for Parmenides is thought, for it is the senses which lead us astray, whereas thought leads to the truth. What is important to stress here is that thought is not the ground or arche of the senses, for then this would mean that thought both is and is not at the same time, rather the realm of thought is completely separate from the realm of senses, and this explains the division of Parmenides’s poem into two parts. This logical division between appearance, which is not, and thought, which is, will be decisive, as we shall see for Plato’s own metaphysics. But before we go to that subject, we shall leave these abstraction behind, and return to more concrete matters of social milieu of the Sophists, and the ethical philosophy of Socrates.
 This difference perhaps needs to be bit clearer. Parmenides too thought that the truth of nature was hidden from most people, but this truth was to be found through logical reasoning (though he would not have called it that), rather than through the senses.
 R.D. McKirahan, Philosophy Before Socrates, (Cambridge: Hackett, 1994), p. 157
 See, D. Sedley, ‘Parmenides and Melissus’ in