History of Western Philosophy - Bertrand Russell [33]
Passing from the small to the large, astronomy no longer allows us to regard the heavenly bodies as everlasting. The planets came out of the sun, and the sun came out of a nebula. It has lasted some time, and will last some time longer; but sooner or later—probably in about a million million years—it will explode, destroying all the planets. So at least the astronomers say; perhaps as the fatal day draws nearer they will find some mistake in their calculations.
The doctrine of the perpetual flux, as taught by Heraclitus, is painful, and science, as we have seen, can do nothing to refute it. One of the main ambitions of philosophers has been to revive hopes that science seemed to have killed. Philosophers, accordingly, have sought, with great persistence, for something not subject to the empire of Time. This search begins with Parmenides.
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5
PARMENIDES
The Greeks were not addicted to moderation, either in their theories or in their practice. Heraclitus maintained that everything changes: Parmenides retorted that nothing changes.
Parmenides was a native of Elea, in the south of Italy, and flourished in the first half of the fifth century B.C. According to Plato, Socrates in his youth (say about the year 450 B.C.) had an interview with Parmenides, then an old man, and learnt much from him. Whether or not this interview is historical, we may at least infer, what is otherwise evident, that Plato himself was influenced by the doctrines of Parmenides. The south Italian and Sicilian philosophers were more inclined to mysticism and religion than those of Ionia, who were on the whole scientific and sceptical in their tendencies. But mathematics, under the influence of Pythagoras, flourished more in Magna Graecia than in Ionia; mathematics at that time, however, was entangled with mysticism. Parmenides was influenced by Pythagoras, but the extent of this influence is conjectural. What makes Parmenides historically important is that he invented a form of metaphysical argument that, in one form or another, is to be found in most subsequent metaphysicians down to and including Hegel. He is often said to have invented logic, but what he really invented was metaphysics based on logic.
The doctrine of Parmenides was set forth in a poem On Nature. He considered the senses deceptive, and condemned the multitude of sensible things as mere illusion. The only true being is 'the One', which is infinite and indivisible. It is not, as in Heraclitus, a union of opposites, since there are no opposites. He apparently thought, for instance, that 'cold' means only 'not hot', and 'dark' means only 'not light'. 'The One' is not conceived by Parmenides as we conceive God; he seems to think of it as material and extended, for he speaks of it as a sphere. But it cannot be divided, because the whole of it is present everywhere.
Parmenides divides his teaching into two parts, called respectively 'the way of truth' and 'the way of opinion'. We need not concern ourselves with the latter. What he says about the way of truth, so far as it has survived, is, in its essential points, as follows:
'Thou canst not know what is not—that is impossible—nor utter it; for it is the same thing that can be thought and that can be.'
'How, then, can what is be going to be in the future? Or how could it come into being? If it came into being, it is not; nor is it if it is going to be in the future. Thus is becoming extinguished and passing away not to be heard of.
'The thing that can be thought and that for the sake of which the thought exists is the same; for you cannot find thought without something that is, as to which it is uttered.'1
The essence of this argument is: When you think, you think of something; when you use a name, it must be the