The Catechism forbids deliberate mutilation, so why is non-therapeutic circumcision allowed?

Mutilation involves altering the body for non-therapeutic reasons in ways that interfere with the body’s ability to function. Circumcision was established by God as a sign of the Old Covenant (Gen. 17:10–14) and practiced by God’s people in obedience to him for thousands of years until it was superseded by baptism (Col. 2:11–14). Therefore, we must assume that God would not establish a ritual for his people that can be considered deliberate mutilation and thus intrinsically immoral. Even so, parents who object to non-therapeutic circumcision have the right to refuse to circumcise their sons as a matter of conscience. They should, however, take care not to make their arguments against circumcision in such ways that it casts aspersion on the legitimate choice of other parents to circumcise.