Paul infamously said in Romans 7:7 that he would not have known coveting was a sin, had the Mosaic law not specified a prohibition against coveting:

5 For while we were in the flesh, the sinful passions, which were aroused by the Law, were at work in the members of our body to bear fruit for death.
6 But now we have been released from the Law, having died to that by which we were bound, so that we serve in newness of the Spirit and not in oldness of the letter.
7 What shall we say then? Is the Law sin? May it never be! On the contrary, I would not have come to know sin except through the Law; for I would not have known about coveting if the Law had not said, “YOU SHALL NOT COVET.“
8 But sin, taking opportunity through the commandment, produced in me coveting of every kind; for apart from the Law sin is dead.
9 I was once alive apart from the Law; but when the commandment came, sin became alive and I died;  (Rom. 7:5-9 NAU)

Did Paul’s wording here leave open the possibility that sin could be identified by human beings upon any basis other than Mosaic Law?