C.S. Lewis Shows Why Teens Absolutely Must Be Taught Critical Thinking

When 16-year-old C.S. Lewis stepped off the train at Great Bookham Railway Station in Surrey, England, that afternoon in February of 1914, he entered the intellectually intense world of his tutor, William T. Kirkpatrick, who was awaiting Lewis’ arrival. Young Lewis quickly learned that “The Great Knock,” as he would later affectionately nickname Kirkpatrick, had no patience for thought or talk that was not backed by logic and evidence, and no tolerance for conversation that did not bear valuable information or ideas.

Young Lewis had never been to Surrey, and as he introduced himself to Kirkpatrick, Lewis attempted to initiate a conversation by idly commenting that Surrey’s scenery appeared “wilder” than he imagined it. Kirkpatrick immediately challenged him, aggressively demanding he clarify exactly what he meant by “wilder” and explain his grounds for such an expectation. Had he seen a map or studied pictures of Surrey’s landscapes? Stunned and humiliated, teenager Lewis sheepishly confessed that he had no sound basis for his expectation or opinion, and “wilder” was an inept word choice.¹  

This rigorous, Socratic method of questioning set the tone for Lewis’ tutelage under Kirkpatrick, and it benefited Lewis immeasurably. For the next three years—the last of his teen years from ages 16 to 19—Lewis lived as a student resident with Kirkpatrick, who rigorously prepared Lewis for college entrance exams by shaping and sharpening Lewis’ critical thinking skills that Lewis is known and admired for today.

As a recently retired high school teacher of the Bible, apologetics, and critical thinking, I find it significant that C.S. Lewis began learning and developing critical thinking skills when he was just a teenager. Amid criticisms of and complaints about the intellectual apathy and dearth of reasoning abilities among many of today’s Gen Z², it was my experience of more than ten years as a classroom teacher of high school juniors and seniors that teenagers do, in fact, have both the capability and the desire to develop critical thinking skills as C.S. Lewis did during his teen years. In fact, I contend that the teen years are the optimal time for training in critical thinking—“the ability to take command of one’s mind in order to determine in a reasonable way what thinking to accept and what to reject”³—for several reasons. 

First, the teen years are prime for learning critical thinking skills because the brain is pliable and growing during the teen years. Neuroscientists inform us that developing and practicing the higher thought processes that critical thinking requires, such as identifying, defining, analyzing, interpreting, assessing, predicting, and concluding, increases the number of neural pathways and boosts myelination, thus building a higher-capacity, stronger, and faster brain during the teen years.⁴ A teen can literally build the kind of brain he or she wants by learning skills in critical thinking.  

Second, it is during the teen years that decisions about careers and life paths are made. Do I attend college? If so, what should I major in and why? Do I attend a technical school or join the military? Do I skip all of that and jump into the workforce after graduation? According to a recent “World Economic Forum’s Future of Jobs” report, critical thinking, and problem-solving top the list of skills employers believe will grow in prominence in the next five years. And skills in self-management such as active learning, resilience, stress tolerance, and flexibility are newly emerging.⁵ Equipping teens with critical thinking skills can broaden their options and opportunities for careers and life paths that will give them the most satisfaction. 

Third, teens face unprecedented obstacles to clear and reasonable thought processes from peer pressure, social media, and advertisers. Regarding advertising, the teen segment is a top consumer demographic in America worth billions of dollars a year.⁶ Thus, in their marketing, advertisers play to teen insecurities, anxieties, desires to be accepted, etc. by telling them what clothes will make them popular, what technology will make them acceptable, etc. Critical thinking equips teens to battle back by thinking for themselves and refusing to allow advertisers, peers, or social media to define them. 

The greatest barrier to clear and concise thinking that teens struggle with may be emotion-based thinking, in which teens allow their feelings—sadness, anger, anxiety, etc.—to sabotage their thought processes and shape a belief or idea about what is true. (Has there ever been a generation of young people who favor feelings over facts and experience over intellect more than Gen Z? Probably not.) Our teens must learn what C.S. Lewis taught in The Abolition of Man: “The heart never takes the place of the head, but it can and should obey it.”⁷ 

Fourth, and most important for our teens who are committed to following Christ, critical thinking equips a young Christian to “love God with all [his or her]… mind” (Mat.22:37) by thinking correctly about God—a skill and discipline of eternal value that can carry them through the ups and downs of both adolescence and adulthood. In the fog of our world’s efforts to make God into its own image, critical thinking skills can clear the air and help teens pursue truth about God and share in C.S. Lewis’ longing he expressed in A Grief Observed: to know “not my idea of God. But God.”⁸  

The Apostle Paul, a well-trained, high-caliber critical thinker himself, wrote in 2 Corinthians 10:5 (ESV):  

“We destroy arguments and every lofty opinion raised against the knowledge of God, and take every thought captive to obey Christ.”

We are instructed to resist gullibly believing every thought that enters our minds, and instead to take each thought captive, examine it for truthfulness, and obey Christ. Critical thinking skills arm a teen’s mind against Satan’s deceptions and traps so he can understand more clearly what and why he believes. 

Critical thinking for the Christian is about testing all ideas first by comparing them with what God already says is true in the Bible, like the Bereans did in Acts 17:11 (ESV):  

 “[The Bereans] were more noble [because] they received the word with all eagerness, examining the Scriptures daily to see if these things were so.”

Christianity is a thinking faith, tested and firmly grounded in logic and reason. Teens desperately need discerning abilities to appreciate this. 

After trying out several approaches to teaching critical thinking skills to my high school students, I settled on a four-fold approach that proved effective in equipping students in four key areas: 

1. Appreciating Truth as Absolute – Students found the acronym T.R.U.E.⁹ easily accessible and helpful in understanding truth as absolute: Truth is Transcendent, Real, Universal, and Exclusive. 

2. Applying Sound Logic – Students grasped the basic laws of logic, such as the law of noncontradiction and the differences between deductive and inductive reasoning. I also included in this section a lesson on how to deal with doubt—much needed among teens today. 

3. Avoiding Logical Fallacies – In this unit, students learned over thirty logical fallacies, including Ad Hominem, straw man, red herring, and the genetic fallacy, which C.S. Lewis dubbed “Chronological Snobbery” in Surprised by Joy.¹⁰ After learning these logical fallacies, it was not unusual for a student to remark to me, “Mr. Starkey, I just heard an ad hominem in the cafeteria today,” or “I read a straw man argument on social media last night.”  (I admit it occasionally caused awkwardness when a student would tell me that they had called out their parent for a logical fallacy at home, but parents accepted it good-naturedly, glad that their child was learning to think!)        

4. Asking Good Questions – High schoolers learned to write Socratic dialogues individually and in teams and discovered the “leave a pebble in their shoe” approach. 

I used a variety of resources (listed at the end of this article) to cobble together a curriculum on critical thinking that was guided by the four objectives above. I appeal to parents who homeschool their kids, and to teachers and administrators in public, private, and Christian (especially) schools to be intentional about offering your teenage students a curriculum—or at least several lessons—dedicated to teaching critical thinking skills. 

Here is one final observation about C.S. Lewis’ experience learning critical thinking skills as a teenager under his tutor, William Kirkpatrick: the lessons occurred over time in a relational setting. Remember that Lewis did not go to a classroom in the morning and return home after school like most students do in our culture today. Lewis was a student resident—he lived in Kirkpatrick’s home with Kirkpatrick and his wife. For Lewis, critical thinking lessons occurred not only in formal lessons, but also in unexpected teachable moments sitting in the house, working in the yard, traveling to the store, etc. with Kirkpatrick. 

The point here is that teaching students to think critically is not just the task of a teacher at school; it is also the responsibility of a parent at home. We who are parents and grandparents know all about teachable moments when kids and teens ask us questions unexpectedly—questions that we are usually not prepared for at that moment! Teaching critical thinking skills well requires ongoing mental interaction between parents and kids as they journey through life together. Whether sitting at the dinner table, riding in the car on a trip to the store, or watching a movie together, let us be prepared to initiate conversations or respond to questions to help our kids become better thinkers so they can have confidence in their own judgments, views, and values rather than relying on someone else’s. 

Interestingly, the Bible’s key verse on education, Deuteronomy 6:7 (ESV), seems to have in mind both the formal, scheduled times of instruction at school (or with a tutor) and the unexpected, teachable moments that occur at home:  

“You shall teach them diligently to your children, and shall talk of them when you sit in your house [formal, planned times], and when you walk by the way [informal, teachable moments] and when you lie down, and when you rise [ongoing and consistently].”

In his autobiography Surprised by Joy, written years after Kirkpatrick’s death, Lewis looked back on his teen years and summarized his appreciation for the influence of “The Old Knock” in his life: “My debt to him is very great, my reverence to this day undiminished.”¹¹  

May Gen Z one day be able to look back on their teen years and express the same appreciation for our influence and efforts as their teachers and parents in helping them to acquire critical thinking skills for their own good and for God’s glory. 

Suggested Critical Thinking Resources for Teachers, Parents, and Teens 

Everyday Debate and Discussion: A Guide to Socratic Conversation, Informal 

Discussion, and Formal Debate by Shelly Johnson 

Guide to Critical Thinking by Linda Elder and Richard Paul 

How to Think: A Crash Course in Critical Thinking by Juan Valdes 

How to Win Every Argument: The Use and Abuse of Logic by Madsen Pirie 

Master Your Mind: Critical Thinking Exercises and Activities to Boost Brain Power and 

Think Smarter by Marcel Danesi 

Practical Critical Thinking for Grades 9-12 by Catherine Connors-Nelson 

The Discovery of Deduction: An Introduction to Formal Logic by Joelle Hodges, Aaron Larsen, and Shelly Johnson 

Renewing Your Mind in a Mindless World: Learning to Think and Act Biblically by James Montgomery Boice  

Street Smarts: Using Questions to Answer Christianity’s Toughest Challenges by Gregory Koukl 

Tactics: A Game Plan for Discussing Your Christian Convictions by Gregory Koukl 

The Fallacy Detective: Thirty-Eight Lessons on How to Recognize Bad Reasoning by Nathaniel Bluedorn and Hans Bluedorn

The Art of Argument: An Introduction to the Informal Fallacies by Aaron Larsen, Joelle Hodge, and Chris Perrin 

The Thinking Toolbox: Thirty-Five Lessons That Will Build Your Reasoning Skills by Nathaniel Bluedorn and Hans Bluedorn 

Your Mind Matters by John R.W. Stott