History of Western Philosophy - Bertrand Russell [35]
This perpetual change in the meanings of words is concealed by the fact that, in general, the change makes no difference to the truth or falsehood of the propositions in which the words occur. If you take any true sentence in which the name 'George Washington' occurs, it will, as a rule, remain true if you substitute the phrase 'the first President of the United States'. There are exceptions to this rule. Before Washington's election, a man might say 'I hope George Washington will be the first President of the United States,' but he would not say 'I hope the first President of the United States will be the first President of the United States' unless he had an unusual passion for the law of identity. But it is easy to make a rule for excluding these exceptional cases, and in those that remain you may substitute for 'George Washington' any descriptive phrase that applies to him alone. And it is only by means of such phrases that we know what we know about him.
Parmenides contends that, since we can now know what is commonly regarded as past, it cannot really be past, but must, in some sense, exist now. Hence he infers that there is no such thing as change. What we have been saying about George Washington meets this argument. It may be said, in a sense, that we have no knowledge of the past. When you recollect, the recollection occurs now, and is not identical with the event recollected. But the recollection affords a description of the past event, and for most practical purposes it is unnecessary to distinguish between the description and what it describes.
This whole argument shows how easy it is to draw metaphysical conclusions from language, and how the only way to avoid fallacious arguments of this kind is to push the logical and psychological study of language further than has been done by most metaphysicians.
I think, however, that, if Parmenides could return from the dead and read what I have been saying, he would regard it as very superficial. 'How do you know,' he would ask, 'that your statements about George Washington refer to a past time? By your own account, the direct reference is to things now present; your recollections, for instance, happen now, not at the time that you think you recollect. If memory is to be accepted as a source of knowledge, the past must be before the mind now, and must therefore in some sense still exist.'
I will not attempt to meet this argument now; it requires a discussion of memory, which is a difficult subject. I have put the argument here to remind the reader that philosophical theories, if they are important, can generally be revived in a new form after being refuted as originally stated. Refutations are seldom final; in most cases, they are only a prelude to further refinements.
What subsequent philosophy, down to quite modern times, accepted from Parmenides, was not the impossibility of all change, which was too violent a paradox, but the indestructibility of substance. The word 'substance' did not occur in his immediate successors, but the concept is already present in their speculations. A substance was supposed to be the persistent subject of varying predicates. As such it became, and remained for more than two thousand years, one of the fundamental concepts of philosophy, psychology, physics, and theology. I shall have much to say about it at a later stage. For the present, I am merely concerned to note that it was introduced as a way of doing justice to the arguments of Parmenides without denying obvious