Can We Really Know Anything for Sure?

In September 2012, Dr. Robert Stackpole, director of the John Paul II Institute of Divine Mercy, began receiving letters from his niece who had just started college in New England. He wrote back to her on a regular basis throughout the year, helping keep her mind and heart open to belief in God in the midst of a secular university in which those truths were being questioned and challenged every day. With her permission, Dr. Stackpole shares his letters with our readers, hoping that other young people will be helped by them to see the truth more clearly in a confused and clouded world. Here is his first letter:

Dear Krystal,

Thank you so much for your wonderful letter. What a delight to hear from you, my favorite niece (OK, my only niece - but still my favorite!). I know very well that the transition from living at home to life in a university dorm can be a huge one, but from what you have written, it sounds as if you are experiencing far more than just a change in lifestyle. Your thinking and your faith are evidently being challenged as never before. It's not necessarily a bad thing: Real wisdom has to pass through a refiner's fire before it can become strong enough to do us much good. Your letter shows that you already being "singed" a bit by the intellectual heat.

I was especially intrigued by one paragraph from your letter, which I will quote back to you here, and then I'll share some thoughts with you about it. You wrote:

It seems that nothing is certain to anyone here at this university, or at least there is no consensus about what to believe. Everyone has a different point of view. For example, one of my profs is a practicing Buddhist. He says that everything that we perceive to be so "real" and troubling is just an illusion; until we learn to "see through" such illusions, we will never be able to chill out and find inner peace. My French professor, on the other hand, is a passionate lover of the novelist Albert Camus. He told us the other day that until we honestly come to terms with our own death, as Camus did, we can never really grow up and become "authentic" individuals (cheerful stuff - especially since his class meets at 8 in the morning when I usually feel half-dead anyway!). Some of the students here don't seem to believe in much of anything at all except their weekend parties and getting drunk on a regular basis - or worse. I made a few friends at the student Environmentalist Club, but they mostly seem to be atheists. They were talking the other day about the latest books they had read by the "New Atheists" such as Hawking and Dawkins, and how the natural sciences such as physics and chemistry are the only things that can be trusted to give us hard facts, the "objective" truth about the world. Anything else, they said, is sheer fantasy or wishful thinking. Of course, I largely kept my mouth shut, not wanting to seem a "dinosaur" to them on first meeting because I think I still believe there's a God. ... I wonder what to think these days. Almost all of these people I meet are very intelligent and sincere, yet they disagree with each other on what to believe. Sometimes I think that in this crazy, "post-modern" world the only prudent thing to be is an "agnostic," a doubter: I mean, just admit that no one can really be sure of anything anymore.

Well, Krystal, you know that I write about these "big questions" for a living (in other words, I get paid for sharing what I think about such things, which is a blessing!). So I doubt you will be surprised if I take the liberty of commenting a bit on your thoughts here, especially your retreat into the safety of "agnosticism." The agnostic claims to not be sure about anything, and as you said, in our so-called "post-modern" world where there is so much disagreement surrounding even the most basic truths about the universe and the meaning of life, agnosticism may seem a safe, humble, and tolerant stance to take.

There is only one problem: I don't think anyone can really take it.

You see, you may claim to be unsure about everything - for example, about the existence of God, about right and wrong, about life after death - but at every minute of the day, from the time you get up in the morning until the time you fall asleep at night, you are living as if something was true; you must believe in something strongly enough to base your daily life upon it. For example, the fact that you bother to get up in the morning at all implies that you believe there is something good or beautiful that is worth getting up in the morning for, at least for one more day. The fact that you feed and clothe yourself implies that you believe pretty strongly that you exist, that you have a body, and that taking, at the very least, minimal care of it may help you move forward in your life journey.

The fact that you may never stop to pray during the day shows that however "agnostic" you may claim to be about the existence of God, you are actually living each day as if He did not exist - or, to be more precise, treating Him each day as if He did not exist. The fact that you open the news page on the internet and recoil with horror when you see the mangled bodies of the victims of another terrorist attack implies that you know for sure that at least some things are "objectively" morally wrong - things that no one ought to do, ever - such as blowing up innocent children on a school bus. If need be, you would support and cooperate with the law enforcement authorities in any reasonable efforts they take to put a stop to such crimes.

The point is, you can't really take the "agnostic" option in any of these areas of life: either you get up in the morning with hope or you don't; either you feed and clothe yourself because it's worthwhile doing so or you don't; either you spend some time relating to God in prayer each day or you don't, you either live out a commitment to basic moral values or you don't. Life goes on. You cannot "sit on the fence" of any big question that affects your daily life - and most of the big questions do - just because you cannot sit on the fence of life. You have to live each day as if something were true, whether you want to or not, and the way you live, on a regular basis anyway, betrays what you really believe.

You haven't taken a philosophy course yet, Krystal, but when you do you will find that the guy who most famously wrestled with this question of "Can I know anything for sure?" was the 17th century French philosopher Rene Descartes. He reasoned like this: It seems at first that I can doubt everything. After all, everything I experience could be nothing more than an illusion or a dream. Still, even if that were the case, there would be one thing I could know for sure: my own existence. For if I am suffering from an illusion, there must be someone here being deceived, and if everything I experience is a dream, there must be someone here doing the dreaming. In other words, I can try to doubt everything, but at least there must be someone here doing the doubting. So Descartes came up with what he believed was the one, rock-bottom certainty, the first, foundational thing we can all be sure of: one's own existence, as a thinking self. "I think, therefore I am," he wrote. And on this rock-bottom truth he tried to build his whole philosophy.

No doubt Descartes was right that we can be certain of our own existence, and it would be self-contradictory to say otherwise. But what he failed to see was that there were many other things he was also sure about at the same time, or he never could have come up with his insight, "I think, therefore I am," in the first place. In fact, there are a whole bunch of common sense and self-evident things we can know for sure, and each one of them is bound up with the others - none of them can stand alone.

For example, just to assert "I think, therefore I am," is to rely upon the validity of the most basic principle of logic, called "The Law of Non-Contradiction." This rule states that "a thing cannot both be true and not be true, in one and the same sense, at one and the same time." Sounds difficult, but really it's as simple as a child's game of peek-a-boo. When you play peek-a-boo with an infant, what is the baby laughing at? He or she is laughing because Mommy's face can either be visible or not visible - but not both at the same time. In other words, the child is laughing in wonder at the discovery of the most basic fact about reality: Direct contraries cannot exist and be true at one and the same moment. Every child knows this. Descartes forgot that he had assumed it to be valid all along. For to say "I think, therefore I am" is at the same time to say "It would be false to say I am not." To know and assert anything as true is to know that its direct opposite is false.

Without realizing it, Descartes also assumed the truth of the general meaningfulness of human language: that the words he was using made sense. To argue as he does that we can attempt to doubt everything because everything we experience might be an illusion or a dream implies that those words "illusion" and "dream" have some real, discernible meaning. Think about it: How would we know what the word "dreaming" means except by contrast with experiences we have had of another state in which we were not dreaming at all, but "awake"? And how would we know what the word "illusion" means except by contrast with experiences we have had where we knew for sure that we were not being deceived at all? Thus, if we were dreaming everything we experience or were deceived about everything we experience, we could not even know the meaning of the words "dream" and "illusion" to begin with!

The plot thickens now because we can only really know the meaning of certain crucial words Descartes used, such as "illusion" and "dream," if we are thinking selves with real physical bodies. After all, how could we ever know what "illusion" means unless we had, at least once in our lives, "unmasked" an illusion with the help of our five bodily senses? In other words, we know what an "illusion" is because at least once in our lives we have double-checked, by further sensory investigation, what merely appeared to be true at first. For example, you may have discovered that stainless steel spoons do not really bend in a simple glass of water - although they appear at first to be bent in the water - because you reached your hand in the water and found, with your bodily sense of touch, that the spoon was still straight. In this way, you "unmasked" a visual illusion and confirmed what an "illusion" is, but you had to rely on the help of your five senses to do it. Again, I can only know what "dreaming" is by contrast with the state of "wakefulness," but what is wakefulness other than the state in which our sensory experiences are supremely vivid and intense? That's why we commonly say, "pinch me and make sure I'm awake"! You can dream a lot of things, but you cannot dream the real feeling of a bodily pinch. So, Descartes thought that we can be sure of our own existence as thinking subjects apart from any sure knowledge that we have physical bodies, but in this he was surely mistaken.

We could go on, Krystal. There are many other things that you and I are sure about - and Descartes was, too, although he didn't realize it. Many philosophers believe that language is essentially a social creation, designed for communication between thinking selves. We seem to have a natural capacity for it, but that capacity in us cannot develop and be put to use apart from interaction with other people. You may have heard of the famous case of Eccles, a 13-and-a-half-year-old girl who had been found isolated from birth from all human contact. She had no "private" language at all, and she could only begin to form the most simple words and sentences after several years of human interaction. In short, the mere fact that Descartes was using human words at all to think and to write out his thoughts implied that he had already interacted with other people, and that with them he had learned to use a common language to express his thoughts and communicate.

Do you see what I am driving at? Descartes thought that the first and foundational thing we could be sure about was our own existence as thinking subjects, but, in fact, we can only be sure about that if we also know for sure, at the same time, that we are physical and social beings, and that basic standards of logic apply to all our statements, and that the words we use have real meaning.

And we could go further. One could argue that there are also basic, self-evident truths of mathematics and morals that everyone knows for sure are true but that no one can strictly "prove." They are simply among the network of common sense beliefs that we all live by every day and never seriously doubt for a moment - and (here is the most important thing) no one has ever come up with any strong reasons for doubting them. Again, Descartes assumed the truth of a whole bunch of these things without even realizing it. And so does every so-called "agnostic" who gets out of bed in the morning and goes about his business.

Philosophers sometimes call these things "self-evident propositions" or "properly basic beliefs." How do we know for sure what these properly basic, indubitable beliefs really are? The 18th century Scottish philosopher Thomas Reid gave us some very simple tests for spotting them:

1) They are universally held (in other words, no one genuinely doubts them, except those whose mental equipment has been impaired by illness, alcohol, or drugs);
2) We are irresistibly drawn to them from childhood;
3) They are indispensable to everyday living. And, I would add, they can sometimes be corroborated in everyday living. (This one is fun, Krystal, because you can tease sophisticated agnostics at your university with it. They live by these "properly basic beliefs" every day, even while claiming to be in doubt. For example, next time you go with one to the pub, order a round of drinks for everyone, and then insist that your agnostic friend pay for them. Watch him squirm and grumble about the unfairness of it all. Yet, if we cannot be sure about anything, that must include the properly basic moral standard of "fairness"!)

Of course, it's possible that something people once thought of as a properly basic belief - for example, that the sun really travels across the sky - might be shown to be fallacious; but the burden of proof lies on the doubters here. Without overwhelming evidence to the contrary, we are surely justified in holding these properly basic beliefs as "true beyond a reasonable doubt."

And of course, philosophers disagree with each other about how these "properly basic beliefs" come to reside in our heads in the first place. Some say that our intellect can come up with them simply by reflecting on our sensory experience of the world. Some say our brains must be "hardwired" by evolution to believe certain things because they help us survive as a species. Some say that at least some of these properly basic beliefs (especially the common standards of "perfection" we have in our minds such as "perfect justice" or a "perfect circle") must have a "transcendent" source. In other words, a source outside of us. Perhaps these standards are beamed into our minds by God, who is Infinite Perfection Himself! I tend to think that the truth lies in a combination of all three of these ways.

Anyway, Krystal, I certainly won't drag you into that debate now. Suffice it to say: You know a lot more things for sure than you may realize - and so did Descartes - and the great thing is that, just by standing on these properly basic beliefs, these common sense realities, you can reach as high as the heavens.

So, when someone at college tells you that the safe and humble thing to do these days is to be a complete agnostic, a doubter, because "you can't be sure of anything at all," just say in reply: "I wouldn't be so sure about that!"

Uncle Robert

Robert Stackpole, STD, is the director of the John Paul II Institute of Divine Mercy, an apostolate of the Marian Fathers of the Immaculate Conception, based in Stockbridge Mass.

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