Mere Christianity

Summary

Mere Christianity is C. S. Lewis's case for, and plain explanation of, the beliefs held in common by Christians of most denominations. In the preface Lewis borrows the phrase "mere Christianity" from the Puritan writer Richard Baxter and compares the shared faith to a hall from which doors open into the rooms of the separate churches; he says he is describing the hall, not recommending a room, and that people must eventually live in a room rather than in the hall. Book I, Right and Wrong as a Clue to the Meaning of the Universe, starts from quarrels. People who argue about fairness appeal to a standard they expect the other person to know, which Lewis calls the Law of Human Nature or Moral Law. He answers the objections that it is only herd instinct or social convention, argues that it is not a description of how people behave but of how they ought to, and concludes that behind it stands a mind more like a lawgiver than like anything in nature. Because everyone breaks this law, he ends the first book by saying that we have real cause for concern before that lawgiver. Book II, What Christians Believe, sets Christianity against atheism, pantheism and dualism, and describes the world as enemy-occupied territory into which the rightful king has landed in disguise. In the chapter called The Shocking Alternative Lewis argues that Jesus' claims to forgive sins and to have always existed leave no room for calling him merely a great moral teacher: he was a lunatic, something worse, or the Son of God. He then presents the atonement as the perfect penitent doing for humanity what it could not do for itself, and names baptism, belief and the Lord's Supper as the means by which the new life is passed on. Book III, Christian Behaviour, compares morality to a fleet of ships that must avoid collisions, keep each ship seaworthy and know where it is going. Lewis treats the four cardinal virtues, social morality, psychoanalysis and moral choice, sexual morality and Christian marriage, and forgiveness, and he calls pride the great sin, the vice from which all others grow. He closes with chapters on charity, hope and faith. Book IV, Beyond Personality, explains the Trinity through the difference between begetting and making, time and eternity, and the image of tin soldiers being turned into living men. Lewis argues that God's aim is not to make people nicer but to make them new creatures, sons of God, and that the self is found only by giving it up. The four books began as BBC radio talks between 1941 and 1944, were printed as Broadcast Talks (1942), Christian Behaviour (1943) and Beyond Personality (1944), and were revised and joined under the present title by Geoffrey Bles in London in 1952.

Top Lessons

• Arguing from the quarrel to the lawgiver

  Lewis's opening argument does not begin with Scripture or miracles but with an ordinary dispute about fairness. He asks the reader to notice that both sides assume a shared standard, and builds his case from there. The method shows how a persuasive argument can start from what the audience already grants.

• The trilemma and its critics

  In Book II Lewis argues that Jesus' claims leave only three options: madness, deception or divinity. The argument became famous and was also widely disputed; philosophers and New Testament scholars have asked whether the options are complete and whether the Gospel sayings are reported exactly. Students can study both the argument and the replies as an exercise in testing premises.

• Pride as the great sin

  Lewis sets pride above sensual sins as the root of the others, because it is essentially competitive and sets the self against God and neighbour. He adds that the humble person will not be thinking about humility at all, but will simply be less occupied with himself.

• Virtue as a settled character

  Lewis treats the cardinal and theological virtues not as rules but as qualities formed by repeated choices. His tennis-player example, in which a skilled player's good shots come from trained habit, makes the classical teaching of Aristotle and Aquinas plain for a radio audience.

Verified Quotes

Medical Lens

The book is moral theology, not medicine, but two passages engage psychiatry directly. In Book III, chapter 4, Morality and Psychoanalysis, Lewis accepts that psychoanalysis may cure abnormal feelings and fears, and distinguishes the psychological raw material a person is given, including irrational fears and perverse impulses, from the moral choices made with it; he argues that God judges the choice rather than the material, a position that has been read alongside later separations of symptom from character. In Book IV he returns to temperament, contrasting a person with a sour, nervous disposition who struggles toward goodness with an easy-natured person who has never been tested. The trilemma in Book II relies on lunacy as one of its alternatives, and some critics have objected that a person with grandiose delusions may also teach wisely; this is a debate about the argument, not a clinical claim by Lewis. These links are interpretive readings.

• Book III, Ch. 4, "Morality and Psychoanalysis"

  Lewis separates psychoanalytic treatment of abnormal fears and impulses from the moral choices a patient makes, and says the treatment of the raw material is a medical matter.

• Book II, Ch. 3, "The Shocking Alternative"

  The trilemma offers lunacy as one explanation for Jesus' claims, using the image of a man who thinks he is a poached egg.

• Book IV, Ch. 10, "Nice People or New Men"

  Lewis contrasts inherited temperament and upbringing with moral effort, arguing that a person with a difficult nervous constitution may be further along than an easy-tempered one.