Ζῆν οὐκ ἄξιος, ὅτῳ μηδὲ εἷς ἐστι χρηστὸς φίλος → Life is not worth living if you do not have at least one friend.
Of persons or arguments: P. and V. πιθανός.
Of arguments: P. ἀναγκαῖος, V. εὐπειθής, πειστήριος.
