Ὅτι οὐ δεῖ πάντως δημοσίᾳ τὰς ἀκροάσεις ἀπαγγέλλειν.
The heading of this piece states its thesis: that lectures need not always be delivered in public. It is the only part the edition prints, so how Himerius argued the case is not preserved here.
Himerius the Sophist Declamations and Orations: Oration 73 in Greek in PDF
Himerius the Sophist Declamations and Orations: Oration 73 in Greek in MD
Part of Declamations and Orations