A Counselor Reflects on Mere Christianity by C.S. Lewis
“Each man is at every moment subjected to several different sets of laws but there is only one of these he is free to disobey. As a body, he is subjected to gravitation and cannot disobey it; if you leave him unsupported in mid-air, he has no more choice about falling than a stone has… He cannot disobey those laws which he shares with other things; but the law he does not share with animals or vegetables or inorganic things, is the one he can disobey if he chooses (p.4-5).” Mere Christianity by C.S. Lewis
Lewis is pointing out that most natural laws are impossible to disobey – gravity, laws of physics, or biological laws regarding health. Try to fly and you will fall. An object at rest stays at rest. Drink poison and you will get sick or die. Yet the moral law, by which we all cry “unfair” and know what we mean, is the only law we can break. We can know right and do wrong.
The other laws we can master. We can learn to fly, understand physics at the molecular level, and make fascinating changes in our body through our understanding of nutrition. Yet the moral law, no matter how much we study it, cannot be mastered.
The moral law is the only law that does not impose its outcome on humanity and it is the only law for which understanding does not result in mastery. That is what it means to be free and fallen (not a reference to the classic rock song).
As you wrestle with the implications of this, also consider Romans 7:21-8:2.
So I find it to be a law that when I want to do right, evil lies close at hand. For I delight in the law of God, in my inner being, but I see in my members another law waging war against the law of my mind and making me captive to the law of sin that dwells in my members. Wretched man that I am! Who will deliver me from this body of death? Thanks be to God through Jesus Christ our Lord! So then, I myself serve the law of God with my mind, but with my flesh I serve the law of sin. There is therefore now no condemnation for those who are in Christ Jesus. For the law of the Spirit of life has set you free in Christ Jesus from the law of sin and death. (emphasis added)
This passage speaks of up to four laws of moral significance: the law of God, the law of my mind, the law of sin, the law of the Spirit of life. From what I understand of the passage, none of these uses of the word law refer to a set of rules, but each has the connotation we use when we say “the law of gravity.”
The reason we can break the moral law and none of the other natural laws is that human nature has been infected with a competing law (the law of sin). This is similar to the law of gravity being infected with the law of aerodynamics as a plane accelerates down the runway. The contradiction of the two does not make either less real, although it can make the moments surrounding take off a bit queasy.
As Christians with a new nature or as non-Christians by the common grace awareness of right and wrong, we live in this turbulence.
Due to this bad infection (Lewis later describes conversion as “good infection”) we are powerless to correct the problem by obeying rules or “doing better.” The broken law is not a violated rule, but a pre-birth bent disposition resisting the “law of God.” For this reason, we need a new nature (2 Cor 5:17) and a new heart (Ezek 36:26). Praise God that is what “mere Christianity” offers through Christ!