Let me see if I can do something to simplify the idea of natural law or, as I would prefer to state it, natural revelation.
A couple of boys go home after school, accompanied by a couple of their unbelieving friends. When they get to the house, they find it clean and in good order. There are some beautiful paintings on the wall, the work of the boys’ mother. On the counter is a tray of brownies, still warm. This is natural law.
On the fridge is a note from mom, telling the the boys to help themselves to the brownies and, after they have done so, would they please help her out by carrying a desk upstairs, a desk she scored that morning in a yard sale. After that, they can do whatever — study, go play ball, whatever they want to do. That is special revelation.
There are three basic ways to screw this up. One way is to separate the two forms of communication, and focus your attention on only one of them. The second way is to focus on the other one. The third way is to accept both forms of revelation, but to treat them as the work of two different mothers. The normal way to respond, the way her sons do, is by accepting all of it from her, each according to its nature, and all part of a well-integrated home life.
If their unbelieving friends argue with them about it, it doesn’t bother the boys. They know who cooked the brownies. And they know they can eat the brownies because the note said they could, and at the same time, they are glad that there are brownies there to eat — they don’t have to settle for eating the note.
To accept the reality of natural law or revelation is not to create an automatic dualism. The fact that others have done this is evidence of dualistic hearts, not a dualistic world. In an ordinary home, moms cook brownies and they leave notes. Only someone with more than a couple of years of philosophy classes could create a problem out of this.
One last comment on why it is important for us to keep a place for natural law — albeit a natural law that is in no way detached or divorced from the holy Scriptures. Natural law contextualizes the Scriptures. “Eat the brownies” makes sense only when there are brownies to eat. Without natural revelation, special revelation is nonsensical.
But more importantly, natural law contextualizes what the Scriptures are referring to when they speak of God as the maker of Heaven and earth. He created the whole show. We live in a time when there is a great deal of postmodern pressure to push our special revelation back into the ghetto of our “faith community,” or, taking it more expansively, our “faith tradition.” But natural law, by definition, involves the whole house, and not just the note on the fridge — which the boys could be pressured into stuffing into the shirt pocket of their faith community.
Special revelation is the specific revelation left to us by the One who created Heaven and earth — the ultimate metanarrative. Both forms of revelation are metanarratives, and apart from the other, neither one is.
At the same time, it is easier for the unbeliever to say that “you Christians have your Bible, and the Muslims have the Koran,” and so on, than it is for them to say “you Christians have your universe, and the Muslims have theirs.” They try to make this last statement, some of them, but the laughter of the crowd is discouraging.
No, the universe is what it is, and that is the spoken word of Jesus. There is of course no place to stand outside the authority of Scripture, but this fact is easier to ignore than the fact that there is no place to stand outside the way reality is. Reality is not optional, and it is necessary for Christians to say that the authoritative law spoken by that reality is not optional either. And if there is any carping left, all we need to do at that stage is point to the note on the fridge.