13 Who is a wise man. As the lust of slandering arises mostly from pride, and as the false conceit of wisdom for the most part generates pride, he therefore speaks here of wisdom. It is usual with hypocrites to exalt and shew off themselves by criminating all others, as the case was formerly with many of the philosophers, who sought glory for themselves by a bitter abuse of all other orders. Such haughtiness as slanderous men swell with and are blinded by, James checked, by denying that the conceit of wisdom, with which men flatter themselves, has in it anything divine; but, on the contrary, he declares that it proceeds from the devil.
Then the meaning is, that supercilious censors, who largely indulge themselves, and at the same time spare none, seem to themselves to be very wise, but are greatly mistaken; for the Lord teaches his people far otherwise, even to be meek, and to be courteous to others. They, then, are alone wise in the sight of God, who connect this meekness with an honest conversation; for they who are severe and inexorable, though they may excel others in many virtues, do not yet follow the right way of wisdom. (124)
(124) “Who is wise and intelligent among you?” let him by a good conduct shew his works in meekness of wisdom.”
The arrangement here is according to what is common in scripture: Wisdom the effect first, then knowledge the cause or what precedes it. In what follows the order is reversed; knowledge distinguishes between good and bad works, and the good ought to be exhibited with that meekness which wisdom dictates.