'Foolishness' in the Bible

The crown of the wise is their wealth [of wisdom],But the foolishness of [closed-minded] fools is [nothing but] folly.

The foolishness of man undermines his way [ruining whatever he undertakes];Then his heart is resentful and rages against the Lord [for, being a fool, he blames the Lord instead of himself].

Foolishness is bound up in the heart of a child;The rod of discipline [correction administered with godly wisdom and lovingkindness] will remove it far from him.

The devising of folly is sin,And the scoffer is repulsive to men.

Even though you pound a [hardened, arrogant] fool [who rejects wisdom] in a mortar with a pestle like grain,Yet his foolishness will not leave him.