* Despite the obvious dangers, their foolishness led them to climb the treacherous cliff face.
* The teacher sighed at the foolishness of her students' constant distractions.
* The foolishness of his decision to invest all his savings in a risky scheme was evident in his empty bank account.
* The foolishness of war is a lesson humanity has learned too many times.
* It was foolishness on her part to trust him after he had lied to her before.