The Aviary Simile in the Theaetetus

Abstract

The following remarks on the aviary simile have been prompted by Professor Hackforth's article in C.Q. January 1938, pp. 27 ff., in which he in turn comments on certain points in Professor Cornford's treatment in his Plato's Theory of Knowledge.Commenting on 199c–d C. (137) suggests that P.'s criticism in that passage might be met by the inclusion in the aviary of ‘complex objects such as the “sum of 7 and 5”.… It is this object (sc. the complex object “the sum of 7 and 5”) that I identify with 11 when I make my false judgement.… False judgement can be explained as the wrong putting together of two pieces of knowledge’—i.e. 11 and ‘the sum of 7 and 5’. C. (138) further suggests that P. has overlooked this possibility because he persists in speaking as if we judged not ‘that the sum of 7 and 5 is 11’ but that ‘12 (the number we are seeking) is 11 (the number we lay hold of)’. H. replies that this criticism of C.'s is not valid because P. understands the knowledge of 11 and 12 to include a knowledge of the various sums that make up these numbers. There could, therefore, be no ‘question of “putting together” such a piece of knowledge as 7 + 5 = 12 with a different piece of knowledge, viz. the knowledge of 12. They are not different pieces; they are the same piece.’