How Do You Know?

by Phillip Brown

            One of the questions that Christians get asked, and people of faith in general, is how are we so sure that we are right. The question might be put in this way; how do you know that your way is the only way? In this article, I want to do three things. First of all, I want to break this question down, so as to make it clear what exactly it is that we are being asked. Secondly, I want to provide a general response to the question. And finally, I want offer a few suggestions about what to keep in mind when responding to this kind of challenge.

            When someone asks how something is known they are typically requesting one of two kinds of information: either what evidence one has to support a given claim, or set of claims, or, in the more radical sense, how can you know anything at all? The former is what one might call scientific skepticism. Essentially, this deals with specific claims to knowledge. The second is philosophical skepticism. This form of skepticism questions whether, or not knowledge is even attainable.

Scientific Skepticism


            Scientific skepticism is, I think, quite reasonable. Very little is epistemologically self-evident. And as such is the case, we have good reasons to ask someone to provide us with good reasons to believe their claims. There is no reason why one should not ask for empirical, or philosophical evidence in any situation wherein a statement is made that something reflects reality. I think that this is especially true where claims regarding subjects like morality, the existence of an historical figure, or even the existence of God are in question. For example if you are going to make a claim that Jesus is who the New Testament says he is, it is perfectly reasonable for someone to respond with questions demanding evidence that your claim displays verisimilitude. Scientific skepticism is a methodologically sound approach to all inquiry and should be kept in mind when trying to determine whether, or not our beliefs are true and justified.

Philosophical Skepticism

            It is not as common for people to ask after whether, or not knowledge is even attainable, but it does come up in conversation from time to time. When this question is encountered, it behooves us to think deeply about the ramifications of the potential answers. Rene Descartes introduced this problem many years ago in his Meditations on First Philosophy. He posited the idea that there might be a demon who is tricking him, and that every site, sound, sensation and smell was all the demon’s creation. He then questioned whether, or not, he could ever actually know if this was the case? In other words, he asked whether, or not we can actually have knowledge of the external world. If the demon hypothesis is true, or even possible, and it is at least possible, how can we ever know anything apart from what the demon shows us? This came to be known as Cartesian skepticism. And it is still debated among philosophers to this day. Though it may seem like a radical claim, it is not altogether unreasonable. At least so far, there does not seem to be a legitimate way out of the predicament.

How Do We Respond?

            A response to either of these two forms of skeptical questions should be prefaced with two other questions. First of all, ask for clarity, that is, ask your interlocutor which of the two kinds of “how do you know” question is being asked. This is important because it will determine your next question. If they are asking the Cartesian skeptical question, then simply tell them that if we cannot attain knowledge about the external world, then it does not matter in any meaningful way whether, or not you have evidence to support your claim. But if the questioner simply wants evidence for a claim that you have made, then it is your responsibility to be able to respond with well-researched, well thought out arguments. Regardless of whether, or not one is a person of faith, an agnostic, or an atheist, the burden of proof is on the one who makes a claim in any given situation.

           The second preface question is slightly more antagonistic sounding, but my experience has shown that it is more than reasonable to ask. Ask the questioner if they are actually willing to change their mind if you provide them with compelling enough evidence? Often, people demand that you give them proof of your beliefs, not because they are genuinely interested, but because they expect that you haven’t got any. If, upon being asked, you present them will a thoroughgoing argument for why you believe, say, Jesus to be just what the Bible says he is, you can then begin to discuss the merits of the evidence that you present.

           Sadly, however, this is not likely to happen. People struggle with what they believe, or disbelieve, in many ways. And often, uninformed preconceptions lock people into a specific mindset and shaking that mindset is indeed a difficult task. Once you begin to show that you are prepared to put up a reasoned defense for your beliefs, you will most likely run into situations where the person decides that they no longer have time to listen to you, that no amount of evidence would be “good enough” for them, or, if they are honest, they will just state their true feelings and say that they really aren’t willing to have their mind changed. At this point, you have two options, you can point out to them that because they are unmoving in their position, continuing the conversation is no longer valuable and walk away, or you can still try to state your case, so that others around you may hear and, hopefully, be convinced. Either way, you have shown that at least you were willing to defend your position rationally and that is a win in itself.

The Take Away

           If nothing else, I want you take away three things from this brief article. First keep in mind that everyone is different and whatever it is that someone believes, or disbelieves, it is likely that they genuinely seek the same answers that you do. They just might be at a different point in their spiritual journey than you are. So when engaging in conversations about how you know, or don’t know something, try to be patient and understanding. Secondly, be open. If someone is honestly interested in the evidence, take your time and go over it with them as many times as they require. This will help you build a rapport with your interlocutor and it gives you many chances to restate your case and improve on your argument. If it becomes clear that they are not interested, or that they genuinely believe that we cannot attain any true knowledge, and if there is no good reason to remain engaged in the conversation, then smile, be polite, and navigate away from the situation with grace. Above all, be firm, fair and as friendly as possible. And remember, when you engage someone in conversation, you may end up being considered by that person a representative of Christians everywhere. You want to represent Christ well.