as have been
baptized in Christ have put on Christ." And man is made a member of
Christ through grace alone.

Some, however, say that they are the cause of grace not by their own
operation, but in so far as God causes grace in the soul when the
sacraments are employed. And they give as an example a man who on
presenting a leaden coin, receives, by the king's command, a hundred
pounds: not as though the leaden coin, by any operation of its own,
caused him to be given that sum of money; this being the effect of
the mere will of the king. Hence Bernard says in a sermon on the
Lord's Supper: "Just as a canon is invested by means of a book, an
abbot by means of a crozier, a bishop by means of a ring, so by the
various sacraments various kinds of grace are conferred." But if we
examine the question properly, we shall see that according to the
above mode the sacraments are mere signs. For the leaden coin is
nothing but a sign of the king's command that this man should receive
money. In like manner the book is a sign of the conferring of a
canonry. Hence, according to this opinion the sacraments of the New
Law would be mere signs of grace; whereas we have it on the authority
of many saints that the sacraments of the New Law not only signify,
but also cause grace.

We must therefore say otherwise, that an efficient cause is twofold,
principal and instrumental. The principal cause works by the power of
its form, to which form the effect is likened; just as fire by its
own heat makes something hot. In this way none but God can cause
grace: since grace is nothing else than a participated likeness of
the Divine Nature, according to 2 Pet. 1:4: "He hath given us most
great and precious promises; that we may be [Vulg.: 'you may be
made'] partakers of the Divine Nature." But the instrumental cause
works not by the power of its form, but only by the motion whereby it
is moved by the principal agent: so that the effect is not likened to
the instrument but to the principal agent: for instance, the couch is
not like the axe, but like the art which is in the craftsman's mind.
And it is thus that the sacraments of the New Law cause grace: for
they are instituted by God to be employed for the purpose of
conferring grace. Hence Augustine says (Contra Faust. xix): "All
these things," viz. pertaining to the sacraments, "are done and pass
away, but the power," viz. of God, "which works by them, remains
ever." Now that is, properly speaking, a