Συγκεκραμένα γὰρ τἀληθῆ τοῖς πλάσμασι παραχαράσσεται ὥστε, τοῦτο δὴ τὸ λεγόμενον, καὶ τὸ ἅλας μωρανθῆναι."For the truth is mixed with fictions to the extent that, as the saying goes, even the salt has become tasteless."
It conveys the idea that truth is corrupted or diluted when mixed with falsehoods, akin to the saying about salt losing its flavor.