Whose Word Can You Trust?

“Take Nobody’s Word For It.”

“Nullius in verba” is the motto of the Royal Society—one of the world’s oldest scientific institutions. Do you know what it means? It means “Take nobody’s word for it.” Now, your first thought should probably be something like: but if I am to take nobody’s word for it, then perhaps I should not take them at their word for it. It would be quite the self-defeating conundrum indeed. Of course, the Royal Society does not intend the motto quite so literally. Yet something close to this interpretation is remarkably common: the thought that a belief is epistemically suspect simply because we acquired it from another person. We can call this ‘The MOTTO’.

In popular discussions, Christians often face objections to their beliefs based upon something like a commitment to ‘The MOTTO’.

We hear that we cannot trust the Gospels because they consist of reports written by fallible human beings about events we cannot observe for ourselves—we can’t just take their word for it.

Miracle reports, we are told, do absolutely nothing unless they are, in some sense, verified by the scientific method, so, again, we cannot just take their word for it. Personal testimonies of religious experiences or seeming acts of divine providence can likewise be dismissed for similar reasons.

Now, I suspect that the underlying sentiment that motivates ‘The MOTTO’ is that testimony is weak when compared to gleaning something for yourself. We even warn one another about rumours or the telephone game, in which a message becomes increasingly distorted as it passes from person to person. Don’t misunderstand me: these warnings are indeed sensible. We, as humans, lie, exaggerate, misremember…and, frankly, misunderstand. But our awareness of these failures runs the risk of hiding a more important truth: that testimony is not a regrettable source of knowledge, but is, rather, one of the main, most indispensable ways in which human knowledge is acquired, preserved, and shared.

So in this short article, I’m going to show that assumptions like ‘The MOTTO’ are not only mistaken, but would, if accepted, strip us of almost everything we ordinarily take ourselves to know, and I’m going to do that by thinking through the implications of accepting something like ‘The MOTTO’ with a fictitious character, Bob.

Introducing Bob, the Physicist

Bob is an early-career physicist who has just finished his doctoral research on the newest, most exciting developments in quantum gravity. But one morning, he begins to reflect seriously—and literally—on the Royal Society’s motto: Nullius in verba!

“Oh my goodness!” Bob exclaims as reality begins to dawn on him. Almost everything he believes about physics, he realises, he learned from lectures, textbooks, published articles, and conversations with other scientists. So he resolves to accept nothing until he has verified it for himself; that seems smart, right?

Bob first returns to the latest papers on quantum gravity, this time planning on checking their findings. But—gasp—he notices that each of those papers is, itself, expecting him to rely on calculations, measurements, and observations performed by other scientists, and reported in the article. Even where the evidence is described in detail, Bob did not gather it for himself.

He realises he’s got to start further back, so he begins chasing down the theoretical background assumed by each paper. Unfortunately for Bob, each of those theories was also developed and reported on by other scientists. Bob realises he must reproduce every relevant calculation, repeat every experiment, and confirm every single relevant observation from the ground up.

Let us be generous here, and assume that somehow, some way, Bob succeeds. Bob repeats every important experiment in the history of physics and confirms every relevant observation.

At last, Bob reclines with a well-earned beverage: he has now confirmed everything. Taking a sip, he reflects once again on the motto: Nullius in verba!

The perpetual problem

At that moment, Bob realises that he trusted every instrument he used in all his experiments. He assumed that the telescopes, the particle detectors, the clocks, and every other measuring device were working and accurate. But why? Well, he believed that because the engineers and technicians told him that they were properly designed and tested. Shock! Horror! Bob’s quest for knowledge had been entirely foiled. So, Bob gets to work reconstructing and rebuilding every instrument he ever used. Along the way, he realises he must verify the principles of engineering and material sciences upon which all their construction depends, and even checks every machine used to manufacture the components, the machines used to make those machines, and so on. Each attempt to eliminate his dependence on others’ testimony reveals yet more dependence.

But still, we can assume he completes this task, too. Surely now he possesses genuine knowledge of physics independent of any testimony? Nope. Every theory he tested, every instrument he constructed, every result he calculated, relied upon something else: mathematics! He has inherited definitions, formalisms, methods, and results from lecturers, textbooks, and generations of mathematicians: he had proven nothing himself! To eliminate testimony, he now needs to reconstruct the relevant mathematics, too, checking every proof back to the pure foundations.

Discriminating trust

Hopefully, you’re beginning to see my point. Bob is actually fairly lucky, because we’ve been generous to Bob: we’ve allowed him to complete tasks that would be physically impossible for anyone else. For all of us, were we to take something like ‘The MOTTO’ seriously, we would never reach a point at which everything we know rests upon what we have personally verified. Human knowledge simply does not work like that—indeed, it cannot work like that.

What does this all mean then? Certainly, not that we should accept testimony at face value. The truth is that almost all of our knowledge depends on a version of testimony, and some testimony is better than others. To properly assess testimony, we would do well to ask some questions: is the speaker in a position to know? Do they possess the relevant expertise—or an incentive to deceive? Are they reporting something they discovered, or something they heard? If the latter, how was the information transmitted? Do other reports corroborate it? These kinds of questions affect how much evidential weight we should assign testimony.

The goal, then, should be something like discriminating trust: neither blind acceptance nor reflexive rejection, but rather, careful assessment.

The same kinds of considerations apply equally to religious claims. It does not follow that every miracle report is credible, every religious experience veridical, or the Gospel accounts indisputably reliable. I hope it’s clear that I haven’t tried to argue that here and each of these claims should be assessed on their own merits.[1] But, and here’s the crucial point, they cannot be reasonably dismissed simply because they reach us through the testimony of others. If that alone were enough to disqualify them, it would also disqualify most of history, science, and…well, almost every domain of knowledge.

So I wish to leave with two concluding remarks. First, if you are inclined to accept ‘The MOTTO’, it may be time to retire it. Second, if ‘The MOTTO’ has led you to dismiss religious claims out of hand, then I invite you to reconsider evaluating them fairly. You may have dismissed them for reasons that would also undermine much of what you take yourself to know.

References

1. For some fantastic resources arguing for each of these see: for the truth of Christianity, Richard Swinburne Is Jesus God? Oxford University Press, (2010); for the reliability of the Gospels, see Lydia McGrew, Testimonies to the Truth: Why You Can trust the Gospels, Deward Publishing, (2023); for the reliability of religious experiences, see Harold A. Netland, Religious Experience and the Knowledge of God: The Evidential Force of Divine Encounters, Baker Academic (2022); for theism, Joshua Rasmussen, How Reason Can Lead to God: A Philosopher’s Bridge to Faith, IVP Academic (2019); and for miracles, see: Craig S. Keener, Miracles Today: The Supernatural Work of God in the Modern World, Baker Academic (2021).

The Doctoral Fellows are a group of doctoral students across a range of fields spanning philosophy, theology and the social sciences, who are part of the OCCA community. They contribute in various ways, including sharing their expertise with the OCCA speaking team and occasionally taking up speaking engagements on behalf of OCCA.