Longinus On the Sublime 32.7.2 ὅτι μέντοι καὶ ἡ χρῆσις τῶν τρόπων, ὥσπερ τἆλλα πάντα καλὰ ἐν λόγοις, προαγωγὸν ἀεὶ πρὸς τὸ ἄμετρον, δῆλον ἤδη, κἂν ἐγὼ μὴ λέγω.
This is an extremely difficult passage. If προαγωγὸν were a form of masculine προαγωγός ("procurer," "tempter," "beguiler"), as the Perseus comment ("Perseus analysis of προαγωγόν:προαγωγός (leading on): masc acc sg") suggests, we would expect the nominative, not the accusative, as a predicate in agreement with ἡ χρῆσις. It seems we have to take προαγωγὸν instead as a neuter nominative second aorist participle of the verb προάγω, with the following translation:
"However, it is also obvious, even without my saying so, that the use of figures of speech, like other literary adornments, is (something) that has always tempted toward excess."