Concupiscence, although it is without doubt born in us, is both an evil and sin; for we are not to judge according to nature, but according to the law whether a thing be sin or not. Whatever is opposed to the law is sin, whether it be born in us, or not.

Moral corruption fighting against the law, for the crucifying and mortifying of which Christ himself died on the cross, if it be not properly sin, then Scripture has not explained to us what the property of any habitual sin is.

Whatever differs from the norm of the law is sin: but concupiscence in the regenerate differs from the norm of the law. Therefore.

This corruption of nature is here forbidden, for it is truly and properly sin, Rom. 6:12 and 7:17. It is the flesh that lusteth against the Spirit, Gal. 5:18; and if sin, it must be contrary to and forbidden by the law.

He, then, who admits not that all the desires of the flesh are sins, and that that disease of concupiscence, which they call a stimulus, is a fountain of sin, must of necessity deny that the transgression of the law is sin.