Mere Christianity | Study Guide

C.S. Lewis

Download a PDF to print or study offline.

Study Guide
Cite This Study Guide

How to Cite This Study Guide

quotation mark graphic


Course Hero. "Mere Christianity Study Guide." Course Hero. 29 Nov. 2017. Web. 15 Nov. 2018. <>.

In text

(Course Hero)



Course Hero. (2017, November 29). Mere Christianity Study Guide. In Course Hero. Retrieved November 15, 2018, from

In text

(Course Hero, 2017)



Course Hero. "Mere Christianity Study Guide." November 29, 2017. Accessed November 15, 2018.


Course Hero, "Mere Christianity Study Guide," November 29, 2017, accessed November 15, 2018,

Mere Christianity | Book 4, Chapter 2 : Beyond Personality: Or First Steps in the Doctrine of the Trinity (The Three-Personal God) | Summary



Lewis delves further into the claim that Christ was begotten by God and therefore is of the same kind as God. It's more complicated than that, Lewis says, for Christ is not exactly like God. In fact, Christianity conceives of a three-person God. Many say they don't believe in a "personal God," but Christianity is the only doctrine that explains "what a being that is beyond personality could be like." The Christian God is not impersonal but rather super-personal.

Lewis explains the concept of the three-person god using the analogy of spatial and temporal dimensions. God is "three Persons while remaining one Being" in the same way "a cube is six squares while remaining one cube." This multidimensional quality of God manifests within the practicing Christian. When a Christian prays, the God within him motivates him to pray to God as part of the path set out by God.

God can only be perceived by a person whose character is clean. It is not, Lewis explains, that God withholds himself from people of vice. Rather, God is like sunlight, which "has no favorites [but] cannot be reflected in a dusty mirror as clearly as in a clean one." The unity of humankind in Christian brotherhood, which resembles "players in one band, or organs in one body," is the optimal situation for God to reveal himself.

Lewis closes by stating the theological points here are science, not something invented by people. People arrived at the three-person God explanation after taking in all the evidence and putting it together. Lewis agrees it would all be simpler if Christianity was made up, but unlike those "people who are inventing religions ... We are dealing with Fact."


Throughout the text Lewis has claimed his moral and religious ideas, like the Law of Human Nature, resemble mathematics. The truth they represent cannot be disputed. It existed prior to human awareness as part of the structure of the universe. He has used reasoning and logic, the tools of science and math, to explain and make a case for Christianity. Now he characterizes Theology—which he always spells with a capital T—as "the science of God." By Theology, Lewis means the science of only the Christian God. Outside of Lewis's usage, theology applies to the study of religion in general. But for Lewis, Christianity is Theology, a science that finds "Fact" (also capitalized) while other religions are merely "made up."

Lewis presents a logical argument that Christian doctrine is an experimental science like any other science. There are two methods of constructing an argument that can produce a logically valid conclusion. (Validity is not an indicator of truth; it merely indicates the argument follows the rules of logic.) Inductive reasoning looks at the available evidence and works backward to formulate a theory, or a possible explanation about what has been observed. Deductive reasoning is the opposite: it begins with a hypothesis or theory and then conducts experiments—or in the case of a logical argument, puts forth premises or claims. In the scientific method, experimental evidence is the standard by which the theory is assessed.

However, inductive reasoning—what Lewis uses here to explain the three-person theory of God—is "weaker" than deductive reasoning when it comes to producing true conclusions. In deductive reasoning, true premises and a valid, or properly structured, argument will generate a true conclusion every time. In inductive reasoning, however, all the premises can be true but the truth of the conclusion is not ensured. Experimental science uses inductive reasoning to generate a hypothesis, and then uses deductive reasoning to test that hypothesis through experimentation. Lewis's metaphor has a flaw: Theology is not like experimental science because there is no way to "test" it experimentally. The three-person God idea is an untested hypothesis arrived at through inductive reasoning. Until it is tested and repeatedly supported by evidence, Lewis's hypothesis cannot be classed with scientific truth.

Cite This Study Guide

information icon Have study documents to share about Mere Christianity? Upload them to earn free Course Hero access!