Ask at the forum if you have an Ancient or Modern Greek query!
Ὠς χαρίεν ἔστʹ ἄνθρωπος, ὅταν ἄνθρωπος ᾗ → What a fine thing a human is, when truly human!
Of persons or arguments: P. and V. πιθανός.
Of arguments: P. ἀναγκαῖος, V. εὐπειθής, πειστήριος.