On Baptism, Against the Donatists

⁸³ Demetrius of the Lesser Leptis said: "We uphold one baptism, because we claim for the Catholic Church alone what is her own. But those who say that heretics baptize truly and lawfully are themselves the men who make, not two, but many baptisms; for since heresies are many in number, the baptisms, too, will be reckoned according to their number."

84. To him we answer: If this were so, then would as many baptisms be reckoned as there are works of the flesh, of which the apostle says "that they which do such things shall not inherit the kingdom of God;" among which are reckoned also heresies; and so many of those very works are tolerated within the Church as though in the chaff, and yet there is one baptism for them all, which is not vitiated by any work of unrighteousness.