Chapter 12. Who to Believe: Epistemic Authority
§5 Case Study: Extraordinary Claims
(Hume and Miracles)
To conclude our study of epistemic authority, we must look at the “limit test” of testimony: the Miracle. A miracle is defined as a violation of the laws of nature—an event that, according to everything we know about how the world works, should be impossible. David Hume famously argued that a Reasonable Person should almost never believe a miracle based on testimony alone.
5.1 The Logic of Proportionality
Hume’s argument is based on a simple, logical weighing of probabilities.
-
The Weight of Nature: Every “law of nature” (like gravity or the fact that dead people stay dead) is supported by a “firm and unalterable experience”—billions of consistent observations over thousands of years.
-
The Weight of Testimony: Human testimony, on the other hand, is frequently flawed. People lie, they are mistaken, they are caught up in religious fervor, or they simply misunderstand what they saw.
5.2 Hume’s Maxim
Hume provides a specific “rule of thumb” for dealing with extraordinary claims:
“No testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavors to establish.”
The Test: If someone tells you they saw a person walk on water, you have two choices:
-
The laws of physics were suspended (a miracle).
-
The person is lying or mistaken (a common human occurrence).
Since #2 happens every day and #1 (by definition) never happens, the Reasonable Person concludes that #2 is the more likely explanation.
5.3 Miracles as Evidence Against God?
Building on Hume, contemporary philosophers like Christine Overall have taken the argument a step further. They argue that if miracles did happen frequently, they would actually make it harder to believe in a rational, orderly Creator.
-
The Problem of Chaos: If a deity frequently suspended the laws of physics, the world would become unpredictable. We couldn’t do science, medicine, or even basic engineering if we couldn’t trust that gravity or chemistry would work the same way today as they did yesterday.
-
Epistemic Responsibility: For Overall, our primary duty is to trust the Natural Laws that allow us to survive and understand the world, rather than chasing “extraordinary” claims that lack extraordinary evidence.
§5 Summary Table: Testing the “Impossible”
| Step | The “Humean” Question | The Goal |
| 1. Assess the Law | How much evidence supports the “normal” way the world works? | Establish the “baseline” of probability. |
| 2. Assess the Source | Is the person telling me this famous for being 100% accurate? | Identify potential human error/bias. |
| 3. Compare | Is it more likely that nature broke, or that a human failed? | Choose the explanation with the least “miraculous” baggage. |
| 4. Conclude | Proportion your belief to the evidence. | Maintain Mitigated Skepticism. |
CHAPTER 12: Final Recap
Knowing “Who to Believe” is perhaps the most practical skill in this course. We have learned to:
-
Value Experience but acknowledge its limits (§1).
-
Identify legitimate Experts and respect Consensus (§2).
-
Protect ourselves from Fake News through Mitigated Skepticism (§3).
-
Achieve Strong Objectivity by seeking out diverse standpoints (§4).
-
Remain skeptical of Extraordinary Claims that lack extraordinary proof (§5).
