sharpness or dullness; cleverness or foolishness
A literary noun contrasting sharpness/intelligence with dullness/foolishness. Rare in modern Japanese; mostly found in classical or formal writing.
In classical texts, it is said that the sharpness or dullness of a sword determines victory or defeat in battle.
彼の論評は、人の利鈍を見抜く鋭さがあった。
His critiques had a sharpness that discerned people's cleverness or foolishness.