IC50 commented on the reaction, of the International Committee for the Defence of Salman Rushdie, to his announcement of his conversion. IC51 printed a letter, from Nicolas Walter, strongly criticising the comment, with a reply. He has written again, but the main part of his letter adds nothing of substance and his side of that argument has already had more space than IC‘s. The new letter ends with these two paragraphs:
PS. You are wrong to say [IC51 p.15] that the speed of light is relative. A well-known principle of modern physics is precisely that the velocity of electro-magnetic radiation — c — is constant, regardless of when or where or how or by whom it is measured. This principle is the basis of the theory of relativity and therefore of much science and technology throughout the present century, and so far as it is true it is certainly an absolute.
PPS. You are also wrong to say that “Nothing Is Absolutely True”. If this is true it is untrue, only if it is untrue is it true, and so on. What is true is that statements about absolute truth are generally meaningless.
Two minutes with any fairly large dictionary will show that many words carry several distinct meanings. When IC50 spoke of “the absolute” it was careful to make clear that this is one such term, referring the reader to definition IV.3 under “absolute” in the Shorter Oxford. It also gave the intended meaning directly, saying “to be absolute is to be unrelated or (the same thing) related to nothing,” and offered “absolute monarch” as an example of the use of the word in a weaker sense. IC51 repeated much of this in answer to a correspondent.
One might have thought this number of safeguards against misunderstanding sufficient, but our correspondent’s eagerness to deal crushing blows (“You are wrong,” “You are also wrong”) leads him to charge past them all, assuming that scientists who use the same word as IC must intend to convey the same meaning.
Thanks largely to Michelson and Morley (with a good deal of help from Penguin Books) most people interested in such things now accept that the speed of light does not vary with circumstances; measurement of it whether moving towards or away from the source gives the same result. It qualifies as constant or invariant but not, in the sense in which IC used the term, as absolute. It relates to the points light passes (only this makes measurement possible) bearing the same relation to them all and, as IC50 made clear and IC51 repeated, anything relating to anything else thereby excludes itself from ranking as absolute in the sense in which IC used the term.
The PPS nearly gets the point but collapses at the last fence. Of NIAT it says: “If this is true it is untrue, only if it is untrue is it true, and so on.” Yes, exactly so. But it follows that statements about absolute (in IC‘s sense) truth are not just “generally” but invariably meaningless. Nothing Is Absolutely True. Why then bother to make the remark? Because only when we know where nonsense and meaninglessness begin can we know how far sense and meaning extend.
Our correspondent asks to be removed from the mailing list, and there is of course no option but to comply; it will be done after this issue has been despatched.
from Ideological Commentary 52, Summer 1991.