Complementarians criticize Webb's hermeneutic. Grudem argues that Webb expects Christians to pursue a "superior ethic" to that found in the New Testament, therefore undermining the authority and sufficiency of Scripture. He claims that Webb and some other evangelicals misconstrue the biblical teaching about both slavery and women, and inappropriately confuse the two. He writes that slavery is tolerated in Scripture but never commanded but in some cases is criticized, whereas wives are explicitly commanded to submit to their husbands and male leadership is never criticized. Additionally, Grudem believes that Webb's "redemptive-movement" hermeneutic (itself a variation of the "trajectory" hermeneutic commonly employed by egalitarians) ultimately relies on subjective judgments that are incapable of producing certainty about ethical views.