Solomon
Proverbs 26:12ESV·traditional attribution

Do you see a man who is wise in his own eyes? There is more hope for a fool than for him.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. A spiritual disease supposed, and that is self-conceit: Seest thou a man? Yes, we see many a one, wise in his own conceit, who has some little sense, but is proud of it, thinks it much more than it is, more than any of his neighbours, have, and enough, so that he needs no more, has such a conceit of his own...

John Gill Reformed Baptist @doctorgill

Seest thou a man wise in his own conceit,.... Or "in his own eyes" (b); as multitudes may be seen, by looking round; man is a creature but of small knowledge in things natural, civil, mechanical, philosophical, moral, or divine; yet greatly conceited for the most part of his knowledge and wisdom.

Jamieson-Fausset-Brown Reformed @jfbcommentary

The self-conceited are taught with more difficulty than the stupid.