διαγνωστικός
From LSJ
τὸ δ' ἡδέως ζῆν καὶ ἱλαρῶς οὐκ ἔξωθέν ἐστιν, ἀλλὰ τοὐναντίον ὁ ἄνθρωπος τοῖς περὶ αὑτὸν πράγμασιν ἡδονὴν καὶ χάριν ὥσπερ ἐκ πηγῆς τοῦ ἤθους προστίθησιν → but a pleasant and happy life comes not from external things, but, on the contrary, man draws on his own character as a source from which to add the element of pleasure and joy to the things which surround him
English (LSJ)
ή, όν,
A able to distinguish, ἀληθῶν καὶ ψευδῶν λόγων S.E.P.2.229, cf. Luc.Salt.74; δ. καὶ διακριτικός Id.Herm.69, cf. Gal.UP5.10; δ. θεωρία Id.1.271; δ. σημεῖα, opp. προγνωστικά, ib. 313. II belonging to a διάγνωσις 11, ὑπομνήματα PLips.34.15 (iv A. D.).