CERTAIN MORAL TRUTHS REALLY ARE COMMON TO all human beings. Because our shoes are wet with evasions the common ground may seem slippery to us, but we all know that we shouldn't murder, shouldn't steal, should honor our parents, should honor God, and so on. "Common moral ground" is a cumbersome term for the foundational principles of morality, and also a little thin; a simpler term is "natural law." Here are a few questions people have concerning this misunderstood concept.
Q: Aren't all sorts of wrongs natural? It is natural to fly into a rage. It's natural to murder.
You're mixing up two different senses of the word "natural." People do fly into rages and do murder, but the question is how we are designed. We are designed with a capacity for anger, to arouse us to the protection of endangered goods. It doesn't follow that anger should be indulged so far that goods are endangered. Aren't we also provided with brakes?
Q: But we violate nature every time we have a cavity filled. Isn't it natural for human beings to transcend their natures?
Saying that we violate the nature of a tooth every time we fill a cavity is like saying that we violate the nature of an automobile every time we plug a leak in the radiator. When we plug the leak, we are fulfilling the design by putting the car back in proper order. In the same way, filling a cavity restores to the tooth its natural function of chewing. Healing does not transcend our nature; it respects it ...
Q: Since you're a Christian, why not just rely on the Bible?
For several reasons, but the best one is the Bible itself testifies to the reality of the natural law.
Q: Does it actually mention natural law?
It doesn't use the term "natural law," but ... Paul mentions the witness of deep conscience when he writes, "When Gentiles who have not the law [of Moses] do by nature what the law requires, ... [t]hey show that what the law requires is written on their hearts, while their conscience also bears witness and their conflicting thoughts accuse or perhaps excuse them." He captures the discipline of natural consequences in the formula, "Do not be deceived; God is not mocked, for whatever a man sows, that he will also reap." The Bible is big on the witness of design-design in general, design in us. And it's remarkable that when the apostles are speaking to pagans, they don't begin with Scripture, but with what the pagans know already-for instance their longing for an "unknown god," which implies knowledge that none of their deities are adequate.
Q: Don't natural law thinkers put too much confidence in the capacity of fallen man to know moral truth?
In his letter to the Christians in Rome, Paul doesn't blame the pagans for not having the truth about God and His moral requirements, but for suppressing and neglecting it. In the Proverbs, the complaint made about "fools" is not primarily that they lack knowledge but that they despise it. In other words, atheism and moral obtuseness are not primarily an intellectual flaw; their most important ingredient is obstinacy. The natural law tradition does not deny these things. It recognizes error, it recognizes obstinacy, and it recognizes self-deception ...
Q: Isn't natural law just a baptized pagan theory?
It's true that the first philosophers to use the term "natural law" were pagans, but the biblical testimony to its reality came earlier still. Besides, if God has made some things plain ... wouldn't you expect the pagan philosophers to notice them? Of course their theories needed correction at many points, but that has been done ...
Q: Isn't the portrayal of God in natural law different from the God of Scripture?
No, it's an incomplete picture of the same one. Nature proclaims its Creator; Scripture tells you who He is. Nature shows you the results of His deeds in creation; Scripture tells you the results of His deeds in history. Nature manifests to you His moral requirements; Scripture tells you what to do about the fact that you don't measure up to them. Scripture is more important because it tells you the plan of salvation, but not even Scripture makes nature superfluous.
-Excerpted from J. Budziszewski's book What We Can't Not Know (Spence Publishing, 2003)