That have no law (ta mh nomon econta). Better, "that have not the law" (the Mosaic law). By nature (pusei). Instrumental case of pusi, old word from puw, to beget. The Gentiles are without the Mosaic law, but not without some knowledge of God in conscience and when they do right "they are a law to themselves" (eautoi eisin nomo). This is an obvious reply to the Jewish critic.