Adam Clarke on Romans 7:17

Now then it is no more I - It is not that I which constitutes reason and conscience, but sin-corrupt and sensual inclinations, that dwelleth in me - that has the entire domination over my reason, darkening my understanding, and perverting my judgment; for which there is condemnation in the law, but no cure. So we find here that there is a principle in the unregenerate man stronger than reason itself; a principle which is, properly speaking, not of the essence of the soul, but acts in it, as its lord, or as a tyrant. This is inbred and indwelling sin - the seed of the serpent; by which the whole soul is darkened, confused, perverted, and excited to rebellion against God.