: Immediately after the sin of our first parent, on
account of the knowledge possessed by Adam, who was fully instructed
about Divine things, both faith and natural reason flourished in man
to such an extent, that there was no need for any signs of faith and
salvation to be prescribed to him, but each one was wont to make
protestation of his faith, by outward signs of his profession,
according as he thought best. But about the time of Abraham faith was
on the wane, many being given over to idolatry. Moreover, by the
growth of carnal concupiscence natural reason was clouded even in
regard to sins against nature. And therefore it was fitting that
then, and not before, circumcision should be instituted, as a
profession of faith and a remedy against carnal concupiscence.

Reply Obj. 2: The observance of the Law was not to be promulgated
until the people were already gathered together: because the law is
ordained to the public good, as we have stated in the Second Part
(I-II, Q. 90, A. 2). Now it behooved the body of the faithful to be
gathered together by a sensible sign, which is necessary in order
that men be united together in any religion, as Augustine says
(Contra Faust. xix). Consequently, it was necessary for circumcision
to be instituted before the giving of the Law. Those Fathers,
however, who lived before the Law, taught their families concerning
Divine things by way of paternal admonition. Hence the Lord said of
Abraham (Gen. 18:19): "I know that he will command his children, and
his household after him to keep the way of the Lord."

Reply Obj. 3: Baptism contains in itself the perfection of salvation,
to which God calls all men, according to 1 Tim. 2:4: "Who will have
all men to be saved." Wherefore Baptism is offered to all nations. On
the other hand circumcision did not contain the perfection of
salvation, but signified it as to be achieved by Christ, Who was to
be born of the Jewish nation. For this reason circumcision was given
to that nation alone.

Reply Obj. 4: The institution of circumcision is as a sign of
Abraham's faith, who believed that himself would be the father of
Christ Who was promised to him: and for this reason it was suitable
that it should be for males only. Again, original sin, against which
circumcision was specially ordained, is contracted from the father,
not from the mother, as was stated in the Second Part (I-II, Q. 81,
A. 5). But Baptism contains the power of Christ, Who is the un