"... A third option is to combine the two aforementioned preferences. We can then see both the warning to teachers and the misuse of the tongue in wrongful teaching as the topos of 3:13-18. The main support for this idea is the earlier suggestion that James has in mind in 3:1-12 teachers who employ their “tongues” to articulate false notions that corrupt the “entire body” (verse 6), i.e., the whole ethos of the church. They are not only formalistic in their profession of the faith (verse 2, “bridle” goes back to 1:26); their example and influence is positively and potently injurious to the community (verse 8). They introduce dangerous and destructive (verses 5, 8) matters, which not only are signs of their self-assumed importance (verse 4), but actively lead people astray (5:19—20). The brief vice list of 3:15 indicates what our author thinks of these teachers’ claim to be “wise and understanding,” a collocation of terms that (in Deuteronomy 1:13-15 LXX) is used of Israel’s tribal judges, who were to set a norm for the nation’s conduct as “a wise and understanding people” (Deuteronomy 4:6; compare Hosea 14:9) ..."

Martin, Ralph P. Word Biblical Commentary: James (p. 127) Zondervan, 1988