Catechism of the Catholic Church

The seventh commandment forbids acts or enterprises that for any reason-selfish or ideological, commercial, or totalitarian-lead to the enslavement of human beings, to their being bought, sold and exchanged like merchandise, in disregard for their personal dignity. It is a sin against the dignity of persons and their fundamental rights to reduce them by violence to their productive value or to a source of profit. St. Paul directed a Christian master to treat his Christian slave "no longer as a slave but more than a slave, as a beloved brother,... both in the flesh and in the Lord." (2297)