Cat gre 14b17-18καὶ ἀντιστρέφει γε, —εἰ γὰρ ἀληθὴς ὁ λόγος ᾧ λέ(18)γομεν ὅτι ἔστιν ἄνθρωπος, ἔστιν ἄνθρωπος·—
Ackrill 1963 engand conversely, if the proposition wherein we allege that he is true, then he is.
http://www2.hf.uio.no/common/apps/permlink/permlink.php?app=polyglotta&context=record&uid=ab42b47f-bb72-11e4-bbf3-001cc4ddf0f4