Opponents of slavery, uncomfortable on shaky constitutional ground, maintained that God's higher law had priority over all imperfect human constitutions and political arrangements. Their proslavery antagonists denied that the U.S. Constitution violated the revealed Word of God. Southern scriptural and constitutional arguments were, at least, of a piece. Together and separately, their doctrine of strict construction placed slavery at the center of the sectional quarrel and the split in American national consciousness. They identified slavery as a system of social relations, not merely a congeries of social and economic interests. Ideally, the Constitution united two social systems – the southern based on slavery, the northern on free labor – by a solemn oath of mutual toleration and respect. George Cheever, in biblical exegesis, and Harriet Beecher Stowe, in didactic fiction, agreed that southern slavery did constitute a comprehensive social system – although one they condemned as sinful, immoral, and a corrupting influence on the best of its slaveholding practitioners.