Whoever trusts in his own mind is a fool, but he who walks in wisdom will be delivered.
Here is, 1. The character of a fool: He trusts to his own heart, to his own wisdom and counsels, his own strength and sufficiency, his own merit and righteousness, and the good opinion he has of himself; he that does so is a fool, for he trusts to that, not only which is deceitful above all things (Jer 17:9), but which has often deceived him.
He that trusteth in his own heart is a fool,.... Since the thoughts and imaginations of the thoughts of the heart are only evil, and that continually; they are vain and vague, sinful and corrupt; the affections are inordinate, the conscience defiled, the understanding darkened, and the will perverse; there is no good thing in it, nor any that comes out of it, but all...
(Compare Pro 3:6-8). walketh wisely--that is, trusting in God (Pro 22:17-19).