John Wesley on Romans 2:14

For when the gentiles - That is, any of them. St. Paul, having refuted the perverse judgment of the Jews concerning the heathens, proceeds to show the just judgment of God against them. He now speaks directly of the heathens, in order to convince the heathens. Yet the concession he makes to these serves more strongly to convince the Jews. Do by nature - That is, without an outward rule; though this also, strictly speaking, is by preventing grace. The things contained in the law - The ten commandments being only the substance of the law of nature. These, not having the written law, are a law unto themselves - That is, what the law is to the Jews, they are, by the grace of God, to themselves; namely, a rule of life.