'Demands' in the Bible

But He answered them, “An evil and adulterous generation demands a sign, but no sign will be given to it except the sign of the prophet Jonah.

As the crowds were increasing, He began saying: “This generation is an evil generation. It demands a sign, but no sign will be given to it except the sign of Jonah.

So, when Gentiles, who do not have the law, instinctively do what the law demands, they are a law to themselves even though they do not have the law.