And let no one contend that the descendants of Abraham might fairly enough have paid tithes, although they had already paid tithes in the loins of their forefather, seeing that paying tithes was an obligation of such a nature as to require constant repetition from each several person, just as the Israelites used to pay such contributions every year all through life to their Levites, to whom were due various tithes from all kinds of produce; whereas baptism is a sacrament of such a nature as is administered once for all, and if one had already received it when in his father, he must be considered as no other than baptized, since he was born of a man who had been himself baptized. Well, whoever thus argues (I will simply say, without discussing the point at length,) should look at circumcision, which was administered once for all, and yet was administered to each person separately and individually. Just as therefore it was necessary in the time of that ancient sacrament for the son of a circumcised man to be himself circumcised, so now the son of one who has been baptized must himself also receive baptism.