Definition

Personal incredulity is a logical fallacy where someone dismisses a claim or argument simply because they find it difficult to understand or believe. The fallacy assumes that if something is hard to grasp, it must not be true.

Examples

Example 1: Science Denial

"I can’t believe how evolution could create such complex life, so it must be false."

Example 2: Technology

"Quantum mechanics just doesn’t make sense to me, so I doubt it’s real science."

Example 3: Everyday Life

"It’s hard to imagine how planes stay in the air. I don’t think it’s possible."

Why It's Flawed

Personal incredulity is flawed because:

  • Difficulty understanding something does not make it false
  • It relies on ignorance or lack of imagination rather than evidence
  • Complex or counterintuitive truths are common in science and life
  • It discourages open-minded inquiry

Arguments should be judged by evidence and logic, not by how easy they are to understand.

How to Spot It

Look for these signs of personal incredulity:

  1. The argument is dismissed because it "doesn’t make sense" to someone
  2. The speaker appeals to their own ignorance or confusion
  3. There is little or no engagement with the actual evidence
  4. Complex ideas are waved away as "impossible" or "absurd"

Example of spotting it: If someone says, "I just can’t believe that’s true," ask if there is actual evidence against the claim.

How to Avoid It

To avoid using or being misled by personal incredulity:

  • Recognize that your understanding is not the measure of truth
  • Be open to learning about complex or unfamiliar topics
  • Seek evidence and expert opinion
  • Ask questions rather than dismissing what you don’t understand

When evaluating a claim, focus on the evidence, not just your own intuition.