top of page
  • Writer's pictureJake

Why Should I Listen to You? A Guide to Testimonial Evidence

Many bold claims are supported by only testimonial evidence. Is this enough? If it is, which testimony should we believed and why? Additionally, what do we do if two experts on a topic tell us contradictory things? A common conclusion is that one needs to somehow become an expert just like them in order to figure out who is correct. But even this is not enough because, as we can see, their level of expertise is not sufficient to reach a unified conclusion. Instead, one must become more knowledgeable and insightful than the experts to somehow stand over them as a judge. But is this the only way to judge between them?

Many say that it is. However, here at The Gordian Knot, we believe this conclusion leads to futile attempts at untangling an interminable knot. There are other solutions at hand. Here we will first defend testimonial evidence as a whole against those who reject it. Then we will set out practical ways to figure out disputes, without having to throw ourselves into monkish study of all things under the sun. In that section, three tests will be offered to evaluate whether or not a given piece of testimonial evidence ought to be believed. Finally, we conclude with how to trust testimonial evidence that has been passed down through time. Many, but not all, examples will be religious in nature, but as always I welcome my non-religious readers.

Why You Can’t Give up on Testimony:

In a recent debate with Trent Horn on the resurrection of Jesus, Matt Dillahunty, a prominent atheist apologist, made some pretty bold claims. In short, he denied the reliability of testimonial evidence as a means of certain knowledge. Instead he imagined a fantasy world of “physical and scientific” evidence that is somehow divorced from testimony and gives us more certain truths.

Scientific Evidence:

Claiming that science is somehow separate from testimony is nonsensical. Scientists set up experiments, bear witness to the results, and then report them to the world. That means science itself is a type of testimonial evidence.

In order for science to advance, a person must witness an event which violates the current understanding of our world. If it didn’t conflict with our current understanding, it would not be a discovery and would not advance our knowledge. Instead it would only reaffirm it. Therefore, all scientific advancement is predicated on the supremacy of testimonial evidence over contemporary scientific theory.

However, that last statement implicitly affirms a false dichotomy, because contemporary scientific theories are shorthand for a set of verified and repeated observations from past scientists, as we indicated earlier. Science is a type of testimony. In other words, even if we imagine, as Dillahunty does, that testimony and current scientific theory are different types of knowledge, we can conclude that testimony can outweigh current scientific theory. Accordingly, we can conclude we ought to reject Dillahunty’s claims and accept testimonial evidence. Of course, if we don’t grant the two are different, Dillahunty’s view collapses entirely, since both options on the table are types of testimonial evidence. Either way, testimony is affirmed.

Physical Evidence:

Even physical evidence is not completely distinct from testimony. All physical evidence presumes testimony in order to relate a thing to a truth claim. Furthermore, all physical evidence making a claim in language or symbol is simply testimony using a physical medium.

To unpack the first claim, let’s imagine that, without speaking, I give you a piece of pottery, a pillow and a picture of George Washington. What can you conclude with the physical evidence alone? Nothing, for you were given no context and the items do not serve to prove or disprove anything, because they are not being referenced in any truth claim. It is only when I pair this with testimonial evidence that you can begin to make judgment. For example: ‘I found this pottery in a ship off of South America dating to 3,000 BC, indicating coastal trade among early peoples.’ ‘This pillow belonged to the murder suspect who was believed to smother his victims.’ ‘This picture of Washington proves he is still alive and lives in Paris.’

By themselves the items had no meaning, no persuasive power, and could not provide evidence to be critically examined. What about a wall of hieroglyphics or a cuneiform tablet from ancient Sumer? These are physical, but they are simply a physical medium for testimonial evidence.

In brief, physical evidence is not an alternative to testimonial evidence. In case one, testimonial evidence is presumed and in case two, it is a medium for testimonial evidence.

But I Don’t Trust Others:

Maybe you are thinking the alternative to testimonial evidence is your own senses. The problem is, you are still trusting testimony- your own! If you disbelieve others because they may be mistaken, does this mean you accept your own testimony as infallible? If you discount testimony because of biases or misaligned incentives, have you considered your own? I would argue that we can and do fool ourselves all of the time. Propping ourselves up as the only arbiters of truth is the height of arrogance.

Even if we personally were somehow immune to all possible bias and deception, we could not possibly build up from the ground a totalizing view of reality without other people’s testimony. If we tried, we would get a few inches forward and die of old age. How would we even have names and basic definitions for things if we didn’t at least believe the testimony of our parents and teachers when they pointed to a picture and told us the brown fuzzy thing was a bear? Or, for that matter, when they pointed at something brown and told us it was brown?

I contend that if the goal is truth, we must work as a team, humbly accepting that none of us can reinvent all the knowledge of mankind without relying on others. It is fine to be skeptical of other people’s claims, but the same standard must be applied to our own claims.

How to Evaluate Testimony:

Thus far, we have shown one would be a fool to deny testimony as a source of information about reality. However, we would also be foolish to accept all testimony. How do we make the distinction?

Epistemic Vantage Point: Could they know?

Imagine someone tells you that aliens exist. You ask them how they know this. One response is, this is just a hunch. Another could be that they saw strange lights in the sky. A third answer could be that they were abducted by a spacecraft full of aliens, probed, and deposited the next day in a farmer’s field.

The first case proves nothing, since there is not even a reference to a means of knowing. The second does reference a means of knowing, however they are only in a position to say they saw something that appeared to be in the sky, at a given time and place. They do not have epistemic access to the origin of the thing witnessed nor the existence of an alien crew . And finally, in the last case, yes. If you saw aliens and rode on their spaceship, you would be in a position to verify their existence.

Therefore, if someone tells you they had this experience, you can conclude that if the experience were true, it would provide strong evidence to substantiate their claim that aliens exist. Naturally, we must examine the reliability of the witness and the validity of the claim as the next step.

Most conspiracy theories collapse when this first standard of witness reliability is applied. When confronted, most conspiracy theorist arbitrarily lower their standard of acceptable evidence so their theory clears the bar, while simultaneously raising the standard when other evidence is presented. Here, it is important to demand a constant standard or to demonstrate their bar is too low by showing what other theories would also make the cut.

For instance, someone claims that people running the government are actually shape-shifting lizards (unfortunately there are a large number of people who buy into this nonsense). Step one, ask them how they know. Step two, after hearing their evidence, confirm they think this is a level of evidence adequate to justify a claim of this scale. Step three, run another argument with a similar level of evidence, which they would not agree with, to show their standard is faulty. Alternatively, see if the evidence for the commonsense view meets those low standards. Maybe the evidence is that they heard from a source inside the White House that they are lizard people. You could point out that if this is the standard, they ought to be equally convinced when an insider says they are human.

Taking a more relevant example, imagine a group of doctors sound the alarm because of fatal health outcomes after administering the COVID-19 vaccine. This sounds serious, but we must take into account the whole picture. For example, imagine 35 doctors got together to announce that the day after giving the vaccine to one of their patients, they died in a car accident. Therefore, they conclude, the vaccine is causing traffic fatalities. Would they be justified in this belief? Of course not; they are not in the position to know this was not random chance. Based on the number of vaccinated people to date and the average traffic fatalities per day, this is exactly what we would expect. These 35 doctors just happened to be the ones who see these inevitable events take place.

Now insert claims like women are experiencing higher menstrual bleeding after the vaccine. This claim is swirling around the internet and is supported by some doctors’ anecdotal evidence. Of course some, if not many doctors and patients, will see this outcome because there are hundreds of thousands of doctors and millions of vaccinated women. What those doctors and patients are not in a position to see is the whole picture. There are random variations in how people’s bodies work and these doctors were the ones who, by random chance, encounter the women with higher bleeding. Elsewhere there were doctors who saw less bleeding and made no note of it. In many more places, the effect was negligible, and again no report was made.

Taken all together, these outcomes form a bell shaped curve. To know if vaccines cause the bleeding, we would need information from a large random sample to determine if the bell shaped curve shifted, or if a tail of the curve got fatter. If those individual doctors don’t have that type of information, we have no reason to believe they are not just commenting on the natural variation we expect to see in the data. You can’t make a claim about an effect as a whole by only witnessing the tail end outcomes in a distribution. That would be like winning the lottery and concluding from your experience that the odds of success are high. No, the odds are something seen when looking at the sum of outcomes, or at least a highly representative sample.

I belabored this section and focused on more examples because this seems to be the largest blind spot for most people. Every day we see people speaking far outside of their field of expertise. Be they athletes or actors talking about economic or social policy, or even teenage girls from Sweden who seek to lecture us on long term climatic shifts, this problem runs rampant in our society. I am not calling for extreme skepticism, nor a blind trust in experts, but rather a humble approach to knowledge that recognizes our limitations and bears them in mind.

Incentives: Are they serious about telling the truth or are they motivated to lie?

What if the person making the claim about aliens is clearly looking for attention and notoriety? What if they want to make the farm they were dropped at into a tourist attraction? If there are incentives which encourage someone to lie, this is a good reason to heavily discount their claim. The big four motivators of wealth, power, pleasure, and honor should each be watched for. On the other side, if the witness is losing these things because of their witness to the truth, that would be good reason to take the claim much more seriously.

There really isn’t much nuance to this section. Simply check out people’s motivations before believing them. It really is common sense. Proving the person making the claim has no incentives to lie or showing the cost the person incurs in making the claim does not prove truthfulness. Rather we are determining sincerity. For instance, radical Islamic suicide bombers are not proving the truth of their ideology by giving up their lives, but they are proving their money is where their mouth is.

Bias and Unintentional Deception: If they could know the truth, and they were to tell it, would it be told without distortion?

Imagine a fundamentalist Baptist were tasked with accurately explaining Islamic, Hindu, or even Roman Catholic doctrine. The first two tests could theoretically be passed, but they will likely fail the third. Other examples could include a materialist explaining a supernatural encounter, a vegetarian commenting on the tastiness of a cut of beef, or an Austrian School economist evaluating the effects of a minimum wage.

Some of those biases bend in the right way and others in the wrong way. The goal here is not to somehow find someone with no biases or blind spots. They don’t exist. Instead, we want to know what those biases are and judge accordingly. Bias does not rule out a testimony, instead it tells us how a testimony could have been distorted as it passed through a given worldview.

Often, talk of bias is in a political context. Practically speaking, there are lots of people who are confused about what news to listen to. Some stick to the news sources that confirm their biases and thus become dogmatic about their side and under-informed about the other. Others attempt to hear both extremes, in an almost Hegelian attempt to synthesize the two. While this does offer exposure to different views, it risks being informed only by the most biased people who distort the truth the most. Furthermore, some assume two extremes are equally as close to the middle, but it is readily apparent this is not the case. In a political context, one needs to look no further than first term Barack Obama. Originally he was against gay marriage, wanted abortion restrictions, and proposed a tax cut for corporations, to name only a few things. Clearly the political Left has moved much more than the political Right. Because one side has become much more extreme, the midpoint between the two has dramatically shifted. Therefore, trying to listen to these extremes will either cause you to abandon one side and resort to the first method out of frustration, remain confused about what the truth could be, or attempt to create a middle position that is dictated by whichever side radicalizes the fastest.

You might think that I will propose a middle view, where we find moderate sources. No, that is not where I am headed. Not only do I think these ‘moderates’ are often hiding their biases, but the middle is always moving, as one side shifts its weight further out on the political see-saw. Instead, find sources from each side which are open about their biases, but do not tout fringe views. Then figure out what facts they have in common. You can be relatively sure these common facts represent authentic news.

Putting Together All Three Tests:

Let’s take a test case like the resurrection of Christ. Test one: there is testimony that Christ died and then appeared alive afterwards. Were there witnesses in a position to verify these facts? Yes, for some saw Him die on the cross and over 500 people saw Him after His death. They don’t claim to have seen Him from a distance or in a crowd, but rather to have touched Him, eaten with Him, and talked to Him. These witnesses spent years with Jesus, so of course they could properly identify Him.

Test two: what were the witnesses’ incentives? They didn’t get much by sticking to their claims, except for persecution due to their testimony. Peter was crucified, John was reportedly thrown in boiling oil, and many were imprisoned, beaten, and defamed. Suffice to say, the incentives were aligned to not preach about a resurrection...and yet they did. So far we’ve established that they were in a position to know the truth and that what they believed to be the truth was taken very seriously and defended at great cost.

Test three: Were they biased? Sure! They had all kinds of biases, as we all do. The real question is whether or not their biases would distort the truth enough to invalidate their testimony. In this case, I believe the answer is no.

The apostle Thomas is an excellent example of my point. Being an apostle, he clearly had biases favoring him to belief in Christ’s prophesied resurrection. However, Thomas holds a high standard of evidence. He wanted to see Christ’s wounds and put his own hands in the nail holes to confirm it was really Jesus. Later, he gets the chance to do exactly this. It appears that if he held biases that were in favor of Christ’s resurrection, these proved true and non-distortionary. If however the biases were false, they were clearly overwhelmed by the evidence that stood before him.

In all of Scripture, Paul must be the most biased against the resurrection. He was actively hunting down and killing Christians and yet he, too, has a physical, literal, encounter with the risen Christ that converts him to Christianity. Comparing Thomas and Paul, we observe two extreme sources: one is pro-Jesus and the other is against Him. However, when both are given the epistemic vantage point to know whether the resurrection happened, both reach the same conclusion- despite their radically different biases and despite the enormous personal cost they both must pay.

Despite these biases, there are shared facts among those who had the epistemic vantage point to witness those facts. Secular, Christian, and Jewish sources all agree on the death of Jesus, the empty tomb, the missing body, and the rise of Christianity in which hundreds of people claim they saw Him resurrected.

But wait a minute, we have another problem. How did this and other information about Jesus ever reach us? It seems it was passed down either orally or in written form over thousands of years. How could the message possibly have stayed intact? So begins the next section.

Transferring Testimony: What does the Church have to do with blockchain technology?

Blockchain technology uses a distributed ledger to verify the authenticity of transactions. In brief, if a transaction is disputed, two questions are asked. First, where does the information originate? Second, does this piece of information match everyone else’s records?

The first authentication question looks vertically by going back to the original trusted source. The second moves horizontally by surveying other trusted sources for continuity. With these methods, an error can be traced down in the same way a genetic mutation could be traced to an individual organism. Currently, this is the height of verification technology. However, the process is hardly new. Contrast this with the writings of Tertullian in 200 AD:

But if there be any [heresies] which are bold enough to plant [their origin] in the midst of the apostolic age, that they may thereby seem to have been handed down by the apostles, because they existed in the time of the apostles, we can say: Let them produce the original records of their churches; let them unfold the roll of their bishops, running down in due succession from the beginning in such a manner that [their first] bishop shall be able to show for his ordainer and predecessor some one of the apostles or of apostolic men—a man, moreover, who continued steadfast with the apostles. For this is the manner in which the apostolic churches transmit their registers: as the church of Smyrna, which records that Polycarp was placed therein by John; as also the church of Rome, which makes Clement to have been ordained in like manner by Peter.

But should they even effect the contrivance [of composing a succession list for themselves], they will not advance a step. For their very doctrine, after comparison with that of the apostles [as contained in other churches], will declare, by its own diversity and contrariety, that it had for its author neither an apostle nor an apostolic man; because, as the apostles would never have taught things which were self-contradictory.” (Tertullian, Against the Heretics, 20 [A.D. 200])

Sound familiar? This is how heresy has always been rooted out of the Church because it works extraordinarily well. This is also our answer to our question from the beginning, “how do we decide between the testimony of experts?” Sticking with the religious examples, we ought to see it is easy. Let’s say you hear well-studied scholars in the Roman Catholic and Reformed Baptist tradition making their cases. Both claim to be teaching what Jesus taught. How do you, someone who is not a scholar, ever decide?

We follow both blockchain logic and Tertullian’s advice: look back and look across. Eventually you will find the Baptist church started in 1612 AD, with no line from the apostles even then. Furthermore, their new and novel doctrines don’t agree with the proverbial distributed ledger. Although today Baptists and other Protestants make up half of all Christians worldwide, they are like black sheep which can trace their origins to a few select mutations in the flock. Certain denominations can trace further back to Luther, Calvin, or Zwingli, but each of them fail our Tertullian-style cross-examination.

Of the original Protestant dissenters, Zwingli alone seems to have had the self-awareness to recognize his radical discontinuity: “In this matter of baptism, if I may be pardoned for saying it, I can only conclude that all the doctors [teachers] have been in error from the time of the apostles.” Wow, everyone has been wrong until he came along! Sorry Zwingli, but you can’t be pardoned for making such a bold claim. As for us, we are free to examine his doctrine and disprove it from Scripture if we wish, but there is really no need to take this arduous path. The power of Church Tradition relieves us of this load, as we see his interpretation is solely his own. Ephesians 2:19-21 says:

19 Consequently, you are no longer foreigners and strangers, but fellow citizens with God’s people and also members of his household, 20 built on the foundation of the apostles and prophets, with Christ Jesus himself as the chief cornerstone. 21 In him the whole building is joined together and rises to become a holy temple in the Lord. 22 And in him you too are being built together to become a dwelling in which God lives by his Spirit.”

How could Zwingli, or any other heretic, claim to be part of the Church when they invent doctrines that were never taught by the apostles and disagree with the teachings found in other apostolic churches? Have they not failed to build on the foundation of the apostles and therefore ultimately on Christ?

Questions and Objections:

Objection: I’m not buying all this stuff. We just can’t know history, especially ancient history.


There are a large amount of skeptics who hold this view. Among many other problems, it is difficult to articulate a principled distinction between separation of time and place. For instance, what is the relevant difference between reading a piece of written testimony from the Dead Sea Scrolls, which are nearly 2,000 years old, and reading a piece of testimonial evidence from thousands of miles away in Japan?

It seems neither time nor distance ought to matter. What does matter are the three tests described in the article- and the confidence we have that they pass those tests.


As referenced previously, science is a study of events in the past and a testimony about them. Again, drawing a distinction between history and science is not as simple as it sounds, especially when the line blurs into studies like evolution or geology.


Not all knowledge can be known with 100% certainty, however if one rejects evidence too quickly, they may miss out on pieces needed to make a highly likely cumulative case. For instance, if we have 7 independent pieces of evidence, each with 65% certainty, the cumulative certainty reaches 97.8%.

Question: What if scholars disagree about what happened in the past, such that we can’t look back and across as is proposed?


One option is to look for yourself, if you have the ability and suspect motivated reasoning, instead of truly scholarly academic disagreement.


Since you are relying on the testimony of others for your explanation of what happened in the past, apply the three rules to see if one or the other scholar is more likely to be believed.


Let’s say two scholars disagree about what was the original unanimous view of the Church through history on baptism. You could apply to the scholars the rule you were applying to church history. Ask where the scholar learned about baptism in church history. You have now moved the evaluation lenses from the history of baptism itself to the meta-question of how the scholars received their knowledge on its history.

You might find one scholar is not citing primary sources and therefore is severed from the original knowledge sources. Alternatively, it could be that one scholar received their instruction from an institution failing in one of the first three rules; this would provide evidence against the validity of their testimony.

As always, comment below or email me at and let me know what you think. I always enjoy feedback, comments and questions.

90 views0 comments


bottom of page