THE LANGUAGE OF INCONSISTENCY

This paper presents an interpretation of inconsistent remarks which subjects made in explaining their erroneous solutions to a difficult deductive problem. Four half-masked cards of the following types were presented: (a) a number in the lower half, (b) a blank in the upper half, (c) a letter in the upper half, and (d) a blank in the lower half. The problem is to say which cards need to be unmasked to determine decisively whether a sentence like ‘A letter is above each number’ is true or false. The original aim was to determine the possible effects of varying the order of the terms in the test sentence: the results were inconclusive. However, the subjects' protocols were of much greater interest. When asked to justify their incorrect solutions, their remarks clearly revealed the operation of irreversible thought processes. Three possible hypotheses about them are considered, and it is argued that one involving dissociation of attention is most plausible.