The Truth About Human Nature According to C. S. Lewis

Regarding the Law of Human Nature C. S. Lewis wrote,

“The idea was that, just as all bodies are governed by the law of gravitation, and organisms by biological laws, so the creature called man also had his law– with this great difference, that a body could not choose whether it obeyed the law of gravitation or not, but a man could choose either to obey the Law of Human Nature or to disobey it.

We may put this in another way. Each man is at every moment subjected to several different sets of law but there is only one of these which 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. As an organism, he is subjected to various biological laws which he cannot disobey any more than an animal can. That is, he cannot disobey those laws which he shares with other things; but the law which is peculiar to his human nature, the law he does not share with animals or vegetables or inorganic things, is the one he can disobey if he chooses.” (Mere Christianity pgs 4-5)

There are many people today who claim that there is no truth. These people call their system of philosophy “post-modernity.” They spend all their time pointing out the exceptions to the rule in order to prove that there is no rule. If one argues for two biological genders for example, they point to the extremely rare exception of the person born with both male and female markers. They then argue that since persons are occasionally born with gender deformities that there are more than two genders. It’s a magicians slight of hand. Having severed it from biology through exception rather than rule, they call it a social construct.  They then push for societies to accept the exceptions as the rule, which devolves into several undefinable genders, foreign to history, that are all based on how one mentally feels rather than the biological state of their birth.

But as Lewis so adeptly explained above, the existence of a Law of Human Nature is not disproved by our not obeying it. This is what the post-modernist believes. They point to the places where men disobey the law to prove there is no law. Rather, the Law of Human Nature, is the only law that we can choose to disobey. In fact, the post-modernists observation of it, their formal complaint about it, and their desire to disprove its existence, is in fact a proof that it does. Why should someone go to such an exorbitant extent to disprove it, creating an entirely new philosophical framework, if they did not actually believe it existed. There would be no need to confront it if it was not readily observable and widely accepted. The Apostle Paul describes the trap that the post-modernist lies in, in this way,

For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. They show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them. (Romans 2:14-15)

There is a single moral code written on the hearts of all men. Back to Lewis:

“but for our present purpose I need only ask the reader to think what a totally different morality would mean. Think of a country where people were admired for running away in battle, or where a man felt proud for double-crossing all the people who had been kindest to him. You might just as well try to imagine a country where two and two made five.” (Mere Christianity pg 7)

The Law of Human Nature exists. Our attempts to do away with it proves its existence. We can choose to disobey it, but our excuses and conflicting thoughts accuse us to our conscience, for we would not make excuses or feel accused if we did not know deep down that there is a Law of Human Nature and that we fall short in its fulfillment. We agree then with Lewis and conclude that “this is the foundation of all clear thinking about ourselves and the universe we live in.” (Mere Christianity pg 8)


Members of Solomon’s Porch Christian Community are meeting currently to discuss C. S. Lewis’ book Mere Christianity every Thursday morning @ 5:30AM at a local Starbucks in Smyrna. Feel free to come and join in the discussion. Contact Pastor Jeremy at for more details.


Leave a Reply