Abstract
Crawshay-Williams defines the scope of his book as the study of statements "put forward with a sort of claim to general acceptance by the company [to which they are addressed]". Perelman and Olbrechts-Tyteca would certainly agree that only such statements are capable of giving rise to controversy. But this point, and one other that I shall mention shortly, are nearly the only ones on which the two books agree. And there is profound disagreement about how even this point is to be interpreted. Crawshay-Williams is interested only in the extent to which the claim to acceptance can be satisfied. The phrase I have just quoted is his definition of statements that are testable. His book is largely a discussion of the tests that can be used to determine the correctness of such statements. The implication is, of course, that any genuine controversy can, in principle, be adjudicated by applying such tests to the statements over which it arises. Perelman and Olbrechts-Tyteca, on the other hand, are primarily interested in ways of expressing the claim to general acceptance. Their book is mainly a study of the means by which a statement, or a series of them, can be put forward so as to claim general acceptance by the company to which it is addressed. For them, controversy consists in claims and counter-claims. It can thus be decisively settled only when a claim is sufficiently overpowering to silence all counter-claims. But such a result can be accomplished only by force or hypnosis, and these settle controversy not by adjudicating it but by abolishing it. Controversy cannot therefore be adjudicated at all, except in relatively trivial cases.