Lesson 32: Personal Incredulity

Spot the Faulty Logic #

“I just can’t imagine how billions of stars could exist in the universe. The numbers are too big to understand, so scientists must be exaggerating.”

Discussion: Talk with your teacher about this example. Does our ability to imagine something determine if it’s true?

How/Why It’s Often Used #

When we encounter information that’s hard to understand or imagine, it’s tempting to doubt it. Our brains prefer things that make intuitive sense. If something is too complex, too large, too small, or too strange to easily picture, we might reject it simply because of that difficulty.

This fallacy is common in discussions of science (especially quantum physics, cosmology, and evolution), technology, and other complex topics. People use their personal confusion as evidence against claims.

Personal Incredulity in Action #

Did you spot the faulty logic? #

The person’s inability to comprehend large numbers doesn’t change astronomical reality. Scientists use instruments and mathematics to study things beyond everyday human experience. Our struggle to imagine something says nothing about whether it’s true.

Second Example #

“I don’t understand how vaccines can be safe when they contain some of the disease they’re protecting against. It doesn’t make sense, so I don’t trust them.”

The Flaw #

Not understanding the science of immunology doesn’t make vaccines unsafe. The biology of how vaccines work is well-established, even if it seems counterintuitive. Personal confusion isn’t evidence against scientific findings.