The Adaptable Educator’s Book Review – Mere Christianity by C.S. Lewis

C.S. Lewis’s Mere Christianity is one of the most durable pieces of twentieth-century Christian apologetics: part sermon, part philosophical essay, part intimate conversation. It began as a series of BBC radio talks delivered during the Second World War, and its compactness—an attempt to state the core of Christian belief plainly and persuasively—remains both its strength and its liability. Lewis writes with the clarity of a public intellectual who wants to be understood by non-specialists; the book’s argumentative trajectory is as deliberate as its prose is conversational.

Lewis organizes his case into four movements. The first (the famous “Law of Human Nature”) attempts an ethical argument for a moral law that transcends mere social convention; the second sets forth the doctrines that, he argues, naturally follow from accepting that moral law; the third turns to Christian practice and virtue; and the fourth pushes into more speculative territory about what Christianity implies for personality, the soul, and the Godhead. This architecture gives the book intellectual momentum: Lewis begins where most readers meet him—common moral experience—and, by slow, analogical steps, escorts the reader toward theological claims that many modern voices treat as remote or anachronistic.

What makes Lewis effective is rhetorical craftsmanship. He seeks not to browbeat but to reason with the reader: he insists on common premises, uses succinct metaphors, and deploys humour and imagination to defuse doctrinal defensiveness. His famous “trilemma” about the identity of Jesus — the pithy claim that Jesus must be either Lord, lunatic, or liar — is not merely polemical but pedagogical: Lewis wants to force clarity. Equally notable is his stylistic strategy of plain speech married to philosophical depth. He can move from homespun analogy to a metaphysical claim with apparent ease, and that mixture—homely and high—makes his prose memorable.

A scholarly critique must note limits as well as virtues. Lewis’s method often presumes sympathetic priors: his moral argument presupposes that moral intuition is sufficiently uniform and authoritative to ground metaphysical conclusions. Readers who are skeptical about shared moral intuition may find the opening gambit less persuasive than Lewis imagines. His theological forays in the final section occasionally rely on imaginative analogy where formal theological argumentation would demand more precision; for those trained in systematic theology, parts of the fourth section can feel speculative and under-argued. There are also moments when the book’s mid-century idiom—gendered idioms, an Anglocentric common sense—dates the text and requires contemporary readers to translate rather than accept wholesale.

Still, these limitations are not merely flaws; they are the price of the book’s central achievement. He sought an ecumenical center—“mere” Christianity—and so intentionally stripped away denominational ballast. In doing so he crafted an apologetic that speaks across confessional lines without collapsing into blandness. For readers seeking a model of public intellectual engagement with religion—one that privileges imagination as much as logic—Lewis remains exemplary.

Mere Christianity is not only an apologetic manual but a piece of rhetorical art: accessible, procedural, and provocative. It invites careful, critical reading rather than passive assent. Whether one accepts the offered conclusions or not, the book rewards readers who attend to how arguments are built from lived experience and how faith, for Lewis, must answer the demands of reason and moral seriousness.