Permissive Laws: Preliminary Thoughts

Does it make sense to talk about a 'permissive law'? Laws are usually thought to prohibit or command. Kant has some interesting thoughts on the idea of a 'permissive law'. I see that the blog kantemplation is trying to grapple with these issues. Kantemplation seems to speak of one permissive law, but it is not quite clear to me why there should be only one, anymore than there should be one law that commands.

Anyway, so Kant has these strange passages in Perpetual Peace where he says we can delay putting into effect the right constitution in certain circumstances, but we cannot delay it foreover. He also uses the term with reference to sex (in both right and ethics), and most importantly (in my view) in his discussion in section 2 of the metaphysics of morals, where we get the juridical postulate of public reason, and in section 16 of the same, where Kant sees of a need for a permissive law to provide a principle for the limits of possible rightful possession.

So, where does God fit into this? Well, one connection is that Kant elsewhere discusses the postulate of God, whereas here he is discussing the juridicial postulate of practical reason. Maybe the permissive law is like a divine command.