Here he delineates the differences: first, one difference common to every sacrament, which is that it bears an image; second, another difference which is proper to sacraments of the New Law, in which the nature of a sacrament is perfectly realized, namely, that it acts as a cause, at: For a sacrament is properly so called because it is a sign of God’s grace and a form of invisible grace in such a manner that it bears its image and is its cause.
Circa primum duo facit: primo ponit sacramentum in genere signi; secundo definit signum, ibi: signum vero est res praeter speciem quam ingerit sensibus, aliquid aliud ex se faciens in cognitionem venire.