ἀδιανοήτως

From LSJ

κατὰ τὸν δεύτερον, φασί, πλοῦν τὰ ἐλάχιστα ληπτέον τῶν κακῶν → we must as second best, as people say, take the least of the evils

Source

Russian (Dvoretsky)

ἀδιανοήτως: неразумно (ἀλογίστως καὶ ἀ. Plat.).

Spanish

sin reflexionar, tontamente