Tag Archives: Peter Kreeft

Columbo’s Logic, Part 2

Recommended reading for clear thinking

Last week, we looked at Greg Koukl‘s classic book Tactics, and how his first “Columbo question”, “What do you mean by that?”, is an application of what’s called the first act of the mind in philosophy. This first act, understanding, is simply recognizing that we have to understand what we’re discussing before we can even hope to be able to decide if it’s true or not. His next critical question to ask is “How did you come to that conclusion?” While the first question addresses the what, this one addresses the why. This serves a couple of purposes: First, the person you’re talking to may have good reasons for holding the position they do, that you hadn’t thought of before, and this gives them the opportunity to share those. But secondly, it places the burden of proof where it belongs – on the person making the claim. As Greg points out, “an argument is different from an assertion… An assertion simply states a point. An argument gives supporting reasons why the point should be taken seriously….”[1] Yet many people haven’t thought through why they hold a certain position. Too often, it’s easier to sit in an echo chamber and not dialogue with people of opposing views who may challenge one’s views and legitimately ask for reasons for the claims made. But this question graciously gives your conversant the benefit of the doubt that they have thought about their position and actually have good reasons for why they hold their view. If they have, now’s their opportunity to convince you. If they haven’t, it can hopefully be a wake-up call for them to examine their beliefs. With that in mind, let’s think about the act of reasoning.

This “third act of the mind”, reasoning, is what allows humans to acquire  knowledge beyond our particular experience, and to abstract from particular truths to universal and/or necessary truths. Reasoning is also where we justify our claims by providing valid arguments. As I mentioned last week, the terms we use, by themselves, can be clear or unclear, but they can’t be true or false. Neither can our arguments; they can only be valid or invalid. What is validity? Peter Kreeft, in his Socratic Logic textbook, defines it thus: “An argument is logically valid when its conclusion necessarily follows from its premises.”[2] He further explains:

“Validity is a relationship between propositions: between the premises of an argument and the conclusion of the argument…. A valid argument gives us certainty about its conclusion. It is not absolute certainty but relative certainty, that is, certainty relative to the premises… certainty that if the premises are true, then the conclusion must be true.”[3]

Validity is the mechanical aspect of reasoning that allows us to know two specific relations between a conclusion and its supporting premises: when a conclusion must be accepted, and when a premise must be rejected. Let me explain. Sometimes, a case is being constructed in front of us, and we can follow the steps from defining the terms, to making statements about the terms, to “connecting the dots” with valid reasoning. In this case, a valid argument built on clearly-defined, true supporting premises will have a true conclusion. There is no other possibility given those three conditions. But oftentimes, we are simply presented with an assertion. This is the scenario Greg addresses with the Columbo tactic when he asks someone to clarify their terms and give their reasons that (hopefully) transform their assertion into a conclusion. He is working backwards, deconstructing the conclusion to check its foundation. And in this scenario, a valid argument with a conclusion known to be false guarantees that at least one of the premises is false. The validity of the reasoning isolates the problem to the premises. Kreeft likens this forwards or backwards reasoning process to following a river from its unpolluted source to its unpolluted conclusion downstream, or tracing pollution downstream back to its polluted source upstream.

These two acts, understanding and reason, are two necessary steps toward the end goal of truth. But truth is only conveyed in propositions, whether that be the supporting statements or the final conclusion. To judge the truth of those statements, we need to look next week at the 2nd act of the mind… judgement. Until then, here’s a little homework: next time you’re in a discussion with someone who holds a different view, politely try asking them for the reasons they hold that view. In the absence of any opportunities like that, examine the foundations for your own views. Are they sound? As Greg says, “Intelligent belief requires reasons”[1], and that is true for Christians, atheists – everyone.


[1] Gregory Koukl, Tactics: A Game Plan for Discussing Your Christian Convictions (Grand Rapids: Zondervan, 2009), p. 60.
[2] Peter Kreeft, Socratic Logic (South Bend: St. Augustine’s Press, 2010), p. 31.
[3] ibid., p. 194-5.

Columbo’s Logic, Part 1

The always inquisitive Detective Columbo.

2014 was a very busy year of reading for me. I’d applied to attend Frank Turek’s Cross-Examined Instructor’s Academy, and there was a veritable mountain of recommended reading to get through beforehand, both from noted Christian apologists and some of the most noteworthy atheist writers. That year was when I read a point-counterpoint debate on the existence of God for the first time. I was admittedly nervous about what points the atheist would make that might rock my world. As it turned out, I had little to fear (the atheist case really isn’t as strong as they like to pretend). But one of the books from that year that I have come back to time and again was Greg Koukl‘s book “Tactics: A Gameplan for Discussing Your Christian Convictions” (read a sample here). This is a classic book of critical reasoning that looks at concepts like self-refuting arguments, the burden of proof, and other basic principles of logic, explained well and with clear examples. One of the principal methods laid out in the book is what Greg calls the “Columbo tactic. Peter Falk’s classic bumbling detective character always ends up catching the bad guy by asking “just one more question”. The answers eventually reveal inconsistencies in the murderer’s alibi and the truth always comes to light. While we may not be hunting criminals, we are hunting for truth. And so Greg encourages a) asking questions of your fellow conversant, and b) actually listening to their responses. This is pretty radical in a world where people tend to talk (or shout) past each other, but isn’t that what actual dialogue should involve? The two primary questions Greg asks are “What do you mean by that?” and “How did you come to that conclusion?”[1] These are simple but very powerful questions because they first clarify what is being debated, and secondly seek to uncover their reasons (or lack thereof) for what they believe.  Although I recognized when I read Tactics that these were effective questions, it wasn’t until I read philosopher Peter Kreeft’s textbook on Socratic Logic in 2015 that I understood why.  Kreeft notes at the beginning of his logic text that “there is one simple, observable behavior that clearly distinguishes humans from both computers and animals: asking questions.”[2] Well, Greg doesn’t just ask any old questions, but rather two insightful questions built on the tried and true foundation of classical logic. These directly address the “three acts of the mind”: understanding, judgement, and reason. Let’s look at each one closer over the next few weeks, starting with understanding.

Understanding, traditionally called the first act of the mind, is what Kreeft says most clearly distinguishes humans from computers: “computers understand nothing; they merely store, process, relate, and regurgitate data.” [3] While judgement and reasoning deal in propositions and arguments, respectively, understanding starts with the foundational level of terms. Terms can’t be true or false by themselves, but they can be clear or unclear. There are often multiple words that might be applicable in a particular situation, and most words have multiple meanings depending on the context. Not defining terms is the most frequent cause of people talking past each other. This is typically unintentional, as each person may simply have a different concept in mind when they hear a certain term. Defining a contentious term in a discussion locks down the word used to the actual concept intended and gets both parties “on the same page”, so to speak. This is especially important with controversial topics that can have a lot of connotations beyond the basic definition. A person may also start out using a word one way and switch mid-discussion to a different meaning. Whether intentional or not, this is actually a logical fallacy called equivocation, and is often used to seemingly prove a point – until we examine the change in meaning midstream. Asking your friend “What do you mean by that?” can help highlight (for both of you) when a word is used inconsistently.

To see how definition helps both parties in a conversation to understand each other better, take, for instance, the controversial topic of abortion. Suppose Susan makes the statement “Abortion is wrong” in a conversation with Beth. If Beth takes “wrong” to mean “illegal”, then she will likely disagree with this premise; it’s not currently illegal (here in America). They might go back and forth and get nowhere because Susan defines the term “wrong” as immoral, while Beth defines it as illegal. But of course, not everything that is wrong is illegal (i.e. killing Jews in Nazi Germany was legal, and even rewarded), while not everything that is illegal is wrong (i.e. owning a Bible in North Korea can get you sentenced to a slave labor camp or executed).

Greg’s advice to ask “What do you mean by that?” early on helps avoid the embarrassing admission after the fact of “we got in a big fight and it turned out we weren’t even talking about the same thing…” On that note, this week’s post comes with some homework: 1) look for opportunities this week to try verifying what people mean (hopefully before getting in a fight!), and 2) think about the words you might be using carelessly, and how clearer terms may help better your own understanding of issues, as well as for people with whom you’re communicating.

Next week, we’ll look at Greg’s second question and how it builds on the third act of the mind, reasoning. Then we’ll circle back to the second act of the mind, judgment, to put everything together.


[1] Gregory Koukl, Tactics: A Game Plan for Discussing Your Christian Convictions (Grand Rapids: Zondervan, 2009), p.49,61.
[2] Peter Kreeft, Socratic Logic (South Bend: St. Augustine’s Press, 2010), p. 35.
[3] ibid. p.36.

The Benefit of Deadlines

Photo credit: FreeImages.com/Pedro Simao

As I’m preparing this year for a big engineering exam, I am reminded of the benefit of deadlines. Yes, I said benefit. As much as I hate the pressure of a deadline, whether it’s on a regular project at work or my upcoming exam, I have to admit, it’s better to have a deadline. The procrastinators out there may disagree at first, but I speak as one of you. And if you’re like me, and have procrastinated and gotten burned before, you know deep down that having an indefinite amount of time to accomplish something is the worst gift we can receive. As I can readily attest, studying can just be blown off too easily without a set goal or deadline, but having a test date set motivates us to study like nothing else. The need to study suddenly becomes very real. As I’m watching videos from a review course, and working through practice problems on my weekends now, and collecting reference books I was missing, and highlighting and underlining and tabbing my books like mad, I’m wishing I’d been this motivated over the last several years! But as important as this exam is to me, this all pales in comparison to the critical importance of being reconciled with God. The Bible warns us that it is appointed once for man to die, then the judgement [Heb 9:27-28]. Sadly, that is one deadline that we often go out of our way to ignore. It’s hard to fix a problem we don’t recognize, so let’s work through two potentially disastrous responses to life’s most important deadline.

Although scientific giant Blaise Pascal lived almost 400 years ago, he diagnosed modern American culture pretty well. He wrote in his Pensées about two dangerous responses to God: diversion and indifference. Although some of the diversions are different now, we still choose to busy ourselves with anything imaginable rather than to think about death or examine our lives. Between our jobs and/or school, and our hobbies, and social media and TV, and encouraging our kids to play on 3 different sports teams at the same time while in band and 10 different after-school activities, we don’t have a minute a day that isn’t filled with hustle and bustle. And though we complain about how busy we are, we actually want the busyness, for it keeps us from contemplation. But, as Pascal warns, “diversion amuses us, and leads us unconsciously to death.”[1] No matter what we fill our days with, we must fill them with something, lest we have time to think, and, as philosopher Peter Kreeft puts it, “look at ourselves and listen to our hearts and see the great gaping hole in our hearts and be terrified, because that hole is so big that nothing but God can fill it. “[2] Man’s solution is to not think about it – “ostrich epistemology” as Kreeft calls it.

But there is also that second pitfall: indifference. The diverted person is too distracted to even notice his car is about to run off a cliff until it is too late; the indifferent see the danger but don’t care. Pascal rightly observes, “The immortality of the soul is a matter which is of so great consequence to us, and which touches us so profoundly, that we must have lost all feeling to be indifferent as to knowing what it is.”[3] And again, “Man’s sensitivity to little things and insensitivity to the greatest things are marks of a strange disorder.”[4] Or as Kreeft puts it, “We are more put out at missing a parking place than at missing our place in Heaven”. [5] Whether this indifference is manifested in a hedonism that says “let us eat, drink, and be merry, for tomorrow we die”, or a nihilistic apathy that asks “what’s the point of caring?”, or an arrogant skepticism that says “I glanced at that and promptly dismissed it since it would interfere with the way I want to live”, it is just as inexcusable. If you’ve lived very long on this earth, you’ve known friends and family who haven’t. Death is one certainty in life, and it doesn’t take long to see that it can come to each of us at any time. Sicknesses, accidents, wars, natural disasters, malicious or negligent actions of others like robbers or drunk drivers – the list of ways we can meet our physical death is long, and nobody can predict how much time they will have. Therefore, it behooves us to make wise use of the time given us, and not put off this critical investigation until tomorrow, when tomorrow isn’t promised to any of us.

Dr. Kreeft, reflecting on Pascal’s longer treatment of these two dangers,  warns that “Diversion and indifference are the devil’s two most successful weapons against faith and salvation, the two widest roads to Hell in today’s world.”[6] They are paths of no resistance, for the first blocks the victim’s view of the danger, and the second dulls the perception of it.  But just as diversion and indifference are not reasonable courses of action for me preparing for my exam, neither are they reasonable paths to follow when it comes to your eternal destiny. As Pascal said, “[T]here are only two classes of persons who can be called reasonable: those who serve God with all of their heart because they know Him and those who seek Him with all their heart because they do not know him.”[7] Listen then, to reason, and seek God while He may be found [Is 55:6-7].


Note: The Pensées (“thoughts” in French) are fragments of Pascal’s uncompleted magnum opus, and were left unorganized at his death at the age of only 39. Different editions organize them differently. If you get a book based on the Krailsheimer numbering, use the reference below with a K. The Brunschvicg numbering is indicated by a B.
[1] Pascal Pensées 171 (B), 414 (K).
[2] Peter Kreeft, Christianity for Modern Pagans: Pascal’s Pensées – Edited, Outlined, & Explained (San Francisco: Ignatius Press, 1993), p. 168.
[3] Pensées, 194 (B), 427 (K)
[4] ibid., 198 (B), 632 (K)
[5] Kreeft, p. 203.
[6] Kreeft, p. 188.
[7]Pascal, 194 (B), 427 (K)

Intellectual Sparring

“I Am Sir Lancelot” by N.C. Wyeth, 1922

Have you ever taken part in a debate, or watched one? A question is proposed. A champion comes forward from each side to show why their answer to the question is correct. In a formal debate, they’ve prepared well in advance. The debate may be oral or a written exchange. Some debates will have the audience vote on who “won” the debate. Hopefully, this isn’t just a popularity contest, with the winner decided based on their charisma or their pithy comebacks. Rather, it should be based on who has justified their view the best, who has defended their conclusion by supporting it with true premises using clear terms. Why? A conclusion that logically follows from true premises using unequivocal terms forms an airtight case. If one side can do that, they have won the debate. But is winning the debate the end goal? With our inherent competitiveness, that tends to be the case, but it shouldn’t be. As philosopher Peter Kreeft points out, the real goal should be for both sides to come to agree on the independent truth, regardless of which one found it first.[1] If you prove your point and win the debate, but nobody changes their mind, what have you actually won? What about the debate between atheists and Christians? Is it just about winning an intellectual battle? On the contrary, this issue, above all others, is far from simply an intellectual exercise or game. There are very serious implications. As Blaise Pascal wrote in his Pensées, “It concerns all our life to know whether the soul be mortal or immortal.”[2]

One danger in debating the topics such as the existence of God, the deity of Jesus, the reliability of the Bible, and so on, is that we can be lulled into seeing it as just a game – a sort of intellectual sparring, a competition to see who can win the argument and beat their rival. But these are not simply interesting questions to ponder, or tricky propositions to show off our reasoning prowess. These are truly life and death problems (greater even than life and death, if the warnings of the Bible are true). Luke tells us in Acts 24 of the apostle Paul’s journey through the Jewish/Roman legal system. There we read of Paul’s encounter with the Governor, Felix. After hearing from Paul’s accusers, then from Paul, Felix put them off and kept Paul under house arrest. Hoping to get a bribe from Paul, Felix would send for him often to converse with him.[Acts 24:26] But of course, Paul never offered the bribe Felix was hoping for, only frightening talk of “righteousness, self-control, and the judgement to come.”[Acts 24:25] Two years passed like this, and Felix was replaced by a new governor, while Paul continued to await a fair trial. Felix had at his disposal the author of almost half the books of the New Testament, and talked to him often. And yet, there was no repentance, no change. It was only a game to him.

Is that you today? Are topics like the existence of God and the historicity of Jesus Christ simply interesting topics to discuss, idle speculations, or maybe even amusing subjects of ridicule? Understand the seriousness of the stakes. Death is a certainty for every one of us, and it may take any of us at a moment’s notice. It behooves us then to do our due diligence when it comes to determining if there is another stage to life that we should be preparing for now, for we know not how soon we may be expected to pass through that door. It’d be good to learn what’s awaiting you on the other side. While strictly speaking, atheism only claims that God does not exist, it typically coincides with a materialistic view that there is nothing supernatural (i.e. beyond nature), and that there is therefore nothing of a person that survives physical death. Under Christianity, that point of physical death is simply a point on a person’s timeline that started shortly before and continues on afterward infinitely. It is only a transition and not an ending. It is a change in container (the material body), but not in content (the immaterial soul). That completely revolutionizes how we perceive difficulties, suffering and other unfairness in life, or the perceived unfairness of an unusually short life.

On the other hand, maybe you are not opposed to God, per se, like the atheist, but are simply indifferent. You see no reason to bother with the question. Consider another observation from Blaise Pascal:

“The immortality of the soul is a matter which is of so great consequence to us, and which touches us so profoundly, that we must have lost all feeling to be indifferent as to knowing what it is. All our actions and thoughts must take such different courses, according as there are or are not eternal joys to hope for, that it is impossible to take one step with sense and judgment, unless we regulate our course by our view of this point which ought to be our ultimate end. Thus our first interest and our first duty is to enlighten ourselves on this subject, whereon depends all our conduct.” [3]

Don’t make the mistake of neglecting that “first duty”. A temporary agnosticism on any subject while you are investigating it is commendable; careful considerations generally turn out better than rash decisions, after all. But prolonged agnosticism is only the trap of apathy and indifference in disguise. You may say that you refuse to choose – that you are agnostic – but as Peter Kreeft has so deftly stated, “to every possible question, life presents three possible answers: Yes, No and Evasion. Death removes the third answer… Death turns agnosticism into atheism. For death turns ‘Tomorrow’ into ‘Never’.”[4] You may not have tomorrow; hence the biblical warning “Today if you hear His voice, do not harden your hearts.”[Heb 4:7] Have you made the right choice? Not sure? Contact me and we can discuss any questions you have.


[1] Kreeft, Peter, Socratic Logic, (South Bend: St. Augustine’s Press, 2010), p. 346. “Socrates sees himself and ‘O’ [the opponent] not as a winner and a loser but as two scientists mutually seeking the truth by testing two alternative hypotheses. Whichever one finds the truth, both are winners.”
[2] Pascal, Blaise, Pascal’s Pensées, (New York: E.P. Dutton & Co, 1958),  p. 63. Kindle Edition.
[3] ibid., p. 55.
[4]Kreeft, Peter, Christianity for Modern Pagans: Pascal’s Pensées Edited, Outlined, & Explained, (San Francisco, Ignatius Press, 1993), pp.299-300.