正しょう気きの沙さ汰た

noun

sound judgment; sane decision; act of a clear mind

Almost always used in negative constructions (e.g., 正気の沙汰ではない) to express that something is crazy, unthinkable, or beyond reason.

• こんな値ね段だんで買かうなんて正しょう気きの沙さ汰たじゃない。

  Buying it at this price is sheer madness.

• 彼かれの行こう動どうは正しょう気きの沙さ汰たとは思おもえない。

  His behavior doesn't seem like the act of a sane person.