The Unwritten Law on the Heart

Paul says Gentiles who do not have the law do by nature what the law requires, showing the work of the law written on their hearts.
Second Temple Judaism had a phrase for that. 2 Baruch speaks of a time when the unwritten law was in force among them, and the works of the commandments were accomplished. The same passage runs on to the coming judgment and the hope of a world that will be renewed.
The parallel is instructive. But it is a parallel, and worth labelling as one - nothing in the sources joins 2 Baruch to Romans 2 as an argument. They sit next to each other in a list of resemblances, which is a weaker and more honest claim.
Scripture links:
- Romans 2:14-15 - the law written on their hearts, their conscience bearing witness.
- 2 Baruch 57:2 - the unwritten law was in force among them.
Paul was not inventing the idea of an unwritten law. He was using one his readers already had.