Mere Christianity

A book written by C.S. Lewis and published in 1952 that comprises Lewis ideas about a basic Christian philosophy that everyone can agree upon. The ideas for the book came from a series of radio talks he gave during WWII. These talks were subsequently published in books Broadcast Talks (1942), Christian Behavior (1943), Beyond Personality (1944). Mere Christianity compiled those ideas into one book that Lewis edited the content to better reflect his later understanding of Christian doctrine.

Mere Christianity is divided into four book sections and then into chapters. The arguments are broken up into the same structure for easy reference.

Lewis's Motives for Writing the Book

 * Lewis wanted to stop divisive discussion about "high Theology or even ecclesiastical history" with non-Christians because "the discussions of those disputed points has no tendency at all to bring an outsider into the Christian fold" (Mere Christianity, Preface viii).
 * Lewis made an analogy of equating Christianity to a building: "['Mere' Christianity] is more lake a hall out of which doors open into several rooms. If I can bring anyone into that hall I shall have done what I attempted. [...] The hall is a place to wait in, a place from which to try the various doors, not a place to live in. For that purpose the worst of the rooms [...] is, I think, preferable" (Preface xv).

Definitions

 * Mere Christianity -- core values and teachings of Christianity that all denominations can agree upon
 * Law of (Human) Nature -- "decent behaviour", which people have a freedom to obey or disobey. This law is created by God.  (editor's note: Lewis struggles to explain this concept)

Chapter 1 - The Law of Human Nature
Law of Human Nature encompasses human behavior and moral codes. Lewis identifies that people have free will to obey or disobey this "Law." Also, Lewis identifies a "standard of behavior that everyone expects one another to follow."

Lewis cites the fact that the majority (if not all) societies existing know and follow the Law of Nature, as evidence for the claim that it is universal to mankind. Although, he does not say it yet, it is obvious that he is trying to set-up a platform on which he can build the notion that god is the necessary law-giver of this "Law," and the ultimate cause for its prevalence in human societies. However, Lewis fails to see that he is defeating his own argument before it even begins. If every society that exist today operate on some basic principles of morality (be compassionate, courageous, charitable, etc.; do not murder, steal, rape, etc.), and this is a profound reason as to how a society flourishes and grows, then does it not grant itself to conclude that perhaps it is not a supernatural cause which is to be credited for these moralities. Rather that societies who admire murder and theft, and scoff compassion and charity, naturally fail to organize into productive societies in the first place. And inevitably destroy themselves, or are destroyed by more socially-productive civilizations.

Like every member of the Great Ape family, humans are not solitary animals, and depend on social interactions to increase the quality of their lives and the chance of their survival. Thus, individuals who do not exhibit a moral sense, who murder and steal unscrupulously from others for example, will not be able to join any functioning society, just as any society that fails to function will itself not survive. Lewis makes the mistake, right from the first chapter, of ignoring any plausible naturalistic explanation for human morality, and falsely assumes that one has to grant him his premises of a supernatural cause for his "Law of Nature."

Chapter 2 - Some Objections
In Chapter 1, Lewis describes the Law of Human Nature. Sometimes, he refers to it as the Law of Nature, which can make the first chapter confusing. Some people believe Lewis is talking about scientific laws such as Physics and Biology. This chapter is meant to be his rebuttal.


 * "I conclude then, that though the differences between people's ideas of Decent Behaviour often make you suspect that there is no real natural Law of Behaviour at all, yet the things we are bound to think about these differences really prove just the opposite. But one word before I  end.  I have  met people who exaggerate the  differences, because they have not distinguished  between differences of morality and differences of belief about facts. For example, one man said to  me, "Three  hundred years ago people in England were putting witches to death.  Was that what you call the Rule of Human  Nature or Right Conduct?"  But surely the reason we do not execute witches is that we do not believe there are such things.  If we did-if  we really thought that there were people going about who had sold themselves to the devil and received supernatural powers from him in return and were using these powers to kill their neighbours or drive them mad  or bring bad weather, surely we  would all agree that if anyone deserved the death penalty, then these filthy quislings did.  There is no difference of moral principle here: the difference is simply about  matter of fact.  It may be a great advance in knowledge not to believe in witches: there is no moral advance in not executing them  when you do not think they are there. You would not call a  man humane for ceasing to set mousetraps if he did so because he believed there were no mice in the house."

We learn that if we believe something, the Natural Law of Behaviour supports us to take action on those beliefs. If we believe that witches exist, we have a right to give them the death penalty. We don't execute witches, anymore, because we don't believe they exist. By this philosophy, if we believe someone (or some group) was the anti-Christ, we would be justified in giving them the death penalty.

Another example if you think all Muslims are terrorists, you have a right to execute them by this moral philosophy. If you don't think all Muslims are terrorists, you don't have that right.

Witch hunts still happen in modern times in South Africa and India (see Wikipedia article "Witch-hunt"). Lewis's philosophy may justify these actions.

Lewis is advocating Christians to examine history from a perspective that if they believed the enemy is a horrible being, they have a right to put that enemy to death. Also, Lewis is advocating that we do not re-examine history from present moral philosophy.

On this point, Lewis's moral philosophy is flawed.

Chapter 3 - The Shocking Alternative
Lewis presents the most famous argument of the book, the Liar, Lunatic or Lord "trilemma" located at the end of the chapter.