Think about the Holocaust in relation to natural law.
Even if the Holocaust doesn’t give you pause in relation to God’s existence, it nevertheless functions as an impasse to comprehension. What was God up to in letting the Holocaust happen? What is God up to in creating the penis?
It will not do to say that the first question is uncertain, but the second certain. If the first question is uncertain, it’s all uncertain.
The Holocaust casts a shadow over reason itself–and therefore natural law.
Who knows what God ultimately made anything for?
There appears to be nothing rational about a good God using (or allowing) the Holocaust to achieve his (her?) ultimate ends, so the Holocaust ought to set all of natural law theorizing into a tailspin.
God’s rational purposes are what are in question with the Holocaust–which means that what constitutes reason is up for grabs everywhere.
After the Holocaust, it borders on dark comedy to assert that, though you have no clue what God was up to with the Holocaust, you nevertheless know what God is up to in other domains of existence–such as what the penis should be used for (reproduction only).