Bridges on Proverbs 12:1
Charles Bridges on Proverbs 12:1

1.  Whoso loveth instruction loveth knowledge: but he that hateth reproof is brutish.
INSTRUCTION, as the contrast teaches, chiefly implies discipline (Judges 8:16. Jeremiah 6:8) — that most needful course for acquiring spiritual knowledge. (Psalm 119:67, 71.) For so contrary is it to our proud hearts, that the submission of the will is our only road to Christian attainment. (Matthew 18:3, 4.) Yet the value of this attainment abundantly covers the cost. (Philippians 3:8.) A faithful Ministry, therefore, is a most valuable blessing; and all instructive discipline may well be loved as “the way of life.” (Chapter 9:8. Psalm 141:5, with chapter 6:23. Compare Psalm 16:7; 94:12; Jeremiah 31:18.)
But that irritable pride, that hates reproof, as if it were an affront to be told of our faults, argues not only want of grace (Chapter 10:17; 15:10), but want of understanding — brutish folly (Isaiah 1:3. Jeremiah 8:7): ‘like the horse, which bites and kicks at the man, who performs a painful operation upon him; though absolutely necessary for removing a dangerous distemper. He is surely a brute, and not a rational creature, who has swallowed poison, and will rather suffer it to take its course, than admit the necessary relief of medicine, lest he should be obliged to confess his folly, in exposing himself to the need of it.’† O for a teachable spirit to “sit at the feet of our Divine Master,” and learn of Him!