In this paper I discuss Housman’s principle of textual criticism that apographs are of no importance in the establishment of a text, and suggest reasons why this should not be a universal rule, with reference to the text of Isaios. Housman was emulated in his notoriously acerbic criticism of other scholars by William Wyse, the major editor of Isaios, and I assess the contributions of three scholars who, exceptionally, met with Housman’s approval and made contributions to the text of Isaios.