C. S. Lewis on Evolution and Intelligent Design, Part 1

| By Michael L. Peterson

This blog series, adapted from this article in Perspectives on Science and Christian Faith, is a comprehensive study of the views of Christian author and apologist C. S. Lewis on the theory of evolution and the argument from intelligent design. It explains how he would distinguish expressly philosophical arguments for a Transcendent Mind from the current claims of the intelligent design (ID) movement to provide scientific evidence for such a reality. It also expounds Lewis’s important distinction between evolution as a highly confirmed scientific theory and evolution as co-opted by naturalistic philosophy. In the end, Lewis’s rich Trinitarian framework—stemming from his commitment to historic orthodoxy, or “mere Christianity”—is developed as a context for how he engaged all human knowledge, which includes his acceptance of evolution as well as his criticism of ill-conceived versions of the design argument.

C. S. Lewis on Evolution and Intelligent Design, Part 1



Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect. 1 Peter 3:15 (NIV)

Probably no other modern Christian thinker fulfills this admonition better than C. S. Lewis as he engaged in what may be called intellectual evangelism, pre-evangelism, natural theology, or apologetics. Consider a well-known passage in Lewis:

If all the world were Christian it might not matter if all the world were uneducated. But, as it is, a cultural life will exist outside the Church whether it exists inside or not. To be ignorant and simple now—not to be able to meet the enemies on their own ground—would be to throw down our weapons [and have] no defense against … intellectual attacks … Good philosophy must exist, if for no other reason, because bad philosophy needs to be answered. The cool intellect must work … against the cool intellect on the other side …1

Lewis is saying here that Christian faith has intellectual content that can effectively engage the best information from all fields of knowledge as well as opposing points of view. This article explores how Lewis relates historic, orthodox belief—or, “mere Christianity”—to the debate between Evolution and intelligent design, and then shows how he incorporates these subjects into his Trinitarian vision of reality.

Early in the twentieth century, some religious groups objected to Evolution because it contradicts a literal interpretation of Genesis. The “creation science” movement was formed to provide scientific support for this position, which included commitment to a young earth (approximately 6,000–10,000 years old), the fixity of biological species, and the direct creation of Adam. The Creation Museum near Cincinnati, Ohio, energetically marketed in parts of the Christian community, represents a relatively recent expression of this approach. In the late 1990s, the “intelligent design” (ID) movement emerged, still rejecting evolutionary principles and purporting to have a hot, new scientific argument for God.

What is Evolution, scientifically speaking? All too briefly, cosmic evolution refers to the process of development of the universe—beginning with the Big Bang 13.7 billion years ago and, through many stages, producing all of the chemical elements, all of the galaxies, planets, and other constituents of the cosmos. Biological evolution refers to the origin and development of life on this planet, through many forms and species, including the appearance of human beings on one branch of the Tree of Life with common genetic ties to chimpanzees and other primates. All of the natural sciences converge and tell this story, from astronomy to geology, from paleontology to biology.

Lewis on Intelligent Design

Lewis stands within the long Christian tradition of natural theology: the enterprise of giving reasons for the existence of an Ultimate Being or God, reasons that are based on some feature of the world rather than on special revelation.2 The classic approaches may be summarized as follows:

  • Cosmological Argument: God as the cause of the existence of the universe
  • Moral Argument: God as the source of moral law and our consciousness of it
  • Teleological Argument: God as the cause of rational, lawful, end-directed order in the universe.

Obviously, the teleological argument is about a Transcendent Intelligence that accounts for the rational order of nature—and supreme intelligence is obviously a characteristic of the theistic deity. Historically, labels such as “argument from design” and “design argument” have also been used to refer to some versions of teleological argument. The various arguments for an Intelligence beyond nature should be seen as forming a “family” of teleological or design-type arguments. In the past several decades, a new approach, drawing from science and articulated in elaborate mathematical detail, has been added to the family:

  • The Fine-Tuning Argument: God as the source of the surprising precision and interrelation of nature’s physical constants, from the beginning state of the universe onward, which makes the universe exactly suited for life, including intelligent life. (The anthropic principle involved here is that the universe is fine-tuned for intelligent life.)3

Clearly, natural theology as a whole includes a number of different kinds of arguments for an Ultimate Being. The cosmological argument keys on the power of the Ultimate Being while the moral argument focuses on its moral nature. Additionally, several arguments fall within the family of design-type arguments. Whereas the intelligence of the Ultimate Being is implicit in the cosmological and moral arguments, it is the explicit conclusion of design-type arguments.

As a classicist, Lewis knew about such traditional lines of reasoning pointing to an Intelligence behind nature. He also added some reasoning of his own, arguing in Miracles that, in order for human thought to be rational, it must be free: we must be able to form beliefs by a logical process that is not completely determined by physical processes in the brain. However, a naturalistic worldview, observes Lewis, assumes that matter and its operations are the foundation of all phenomena, including what we call rational thought. It is at this very point that he says Naturalism is self-defeating: it undercuts rational thought by subsuming it under physical causation and therefore removes any basis for regarding human thought as rational, and for regarding the naturalist’s belief in Naturalism as rational.4 Lewis further argues that finite rationality is best explained by something outside of nature which must be more like a Mind than anything else. This is Lewis’s “argument from reason”—not technically a design-type argument but a closely related consideration pertaining to a Transcendent Intelligence.

Lewis also advanced a fascinating “argument from desire”: it begins with the idea that every natural human desire (such as hunger and thirst) corresponds to some real object which satisfies that desire (food, water). But human beings also have a deep natural longing which cannot be satisfied by finite and temporal things, no matter how good or beautiful, and can only be satisfied by something Infinite. This poignant human longing—which Lewis calls by the German word Sehnsucht—is best understood as the deep desire for enduring joy, which, of course, the temporal realm does not contain. The conclusion, then, is that there must be an Ultimate Being, which people call God, whose existence alone can satisfy this longing. I cannot pursue the nuances of this argument here, but certainly the satisfaction of this natural desire of rational creatures would require a rational Being. So, the idea of a Transcendent Intelligence is implicit in this interesting piece of reasoning.

Additionally, all readers and interpreters of Lewis know how effectively he employed his own version of the moral argument. From the arsenal of traditional natural theology, he seemed to prefer this argument, which launches the discussion in Mere Christianity and permeates Abolition of Man.5 And a Supreme Being as a Source of Moral Law would necessarily be rational in nature. A fair summary of Lewis, then, on the possibility of arguing for an Intelligence beyond nature is that he embraced several lines of reasoning in which this theme is either implicit or explicit. Interestingly, however, none of these lines of reasoning are really design-type arguments—and we shall explore the reasons for this in my next post.


1. C. S. Lewis, “On Learning in Wartime” in The Weight of Glory: And Other Addresses, ed. Walter Hooper (1949; revised, New York: HarperOne, 1980), 47–63.

2. See Peterson et al., Reason and Religious Belief: An Introduction to the Philosophy of Religion, 4th ed. (New York: Oxford University Press, 2009), 8 and 90–122. It should be noted that the Reformed objection to natural theology (advanced by Alvin Plantinga and others) argues both that some assumptions underlying the argument strategy of natural theology are too strong and that there are conditions under which a person is rationally warranted in believing in God without providing an argument for God’s existence. But this simply means that we must refine our understanding of the project of natural theology and its arguments, not that there is no viable conception of natural theology. For further discussion of this approach, see Reason and Religious Belief, 123–4. To consult key primary sources on natural theology as well as the Reformed objection, consult the companion volume: Peterson et al., eds., Philosophy of Religion: Selected Readings, 4th ed. (New York: Oxford University Press, 2010), Parts 5 and 6.

3. See Peterson, Reason and Religious Belief, 206–8. See also Peterson, Philosophy of Religion, 222–30. Owen Gingerich, “What is the ‘fine-tuning’ of the universe, and how does it serve as a ‘pointer to God’?” 

4. This argument is made in “The Cardinal Difficulty of Naturalism” in Lewis, Miracles (1947; reprint, San Francisco, CA: Harper San Francisco, 1960), chap. 3. More recently, Alvin Plantinga has offered his own argument, quite reminiscent of Lewis’s, that Naturalism is self-defeating: Plantinga’s evolutionary argument against Naturalism is that the conjunction of biological evolutionary theory and philosophical naturalism makes the probability low that we have reliable cognitive faculties that can produce warranted beliefs. On the other hand, there is no such low probability on the conjunction of biological evolution and Theism. Plantinga first proposed the argument in Warrant and Proper Function but improves it in his Warranted Christian Belief (New York: Oxford University Press, 2000), 228–9. For a helpful discussion of this approach, see James Beilby, ed.,Naturalism Defeated? Essays on Plantinga’s Evolutionary Argument against Naturalism (Ithaca, NY: Cornell University Press, 2002). For a book-length debate which involves this argument, see Daniel Dennett and Alvin Plantinga, Science and Religion: Are They Compatible? (New York: Oxford University Press, forthcoming 2011).

5. Lewis, Mere Christianity, Book I; The Abolition of Man (1947; reprint, New York: HarperOne, 1974).


About the Author

Michael L. Peterson

Michael L. Peterson is professor of philosophy at Asbury University. He is also managing editor of Faith and Philosophy: Journal of the Society of Christian Philosophers. His books include Reason and Religious Belief (Oxford); God and Evil(Westview); With All Your Mind: A Christian Philosophy of Education (Notre Dame); and Evil and the Christian God(Baker). He has produced multiple edited volumes and journal articles.