Fallacies: D (Part 2)

Core idea

The second half of D leans into folklore and wishful thinking: an unbreakable diamond, a clairvoyant dog, a brave Dutch boy who never existed. Several of these myths persist not because the evidence supports them but because the story is better than the truth. The picturesque, as the book puts it, drives out common sense whenever the two compete.

Why it matters

A myth that survives on charm is harder to kill than one that survives on a mistake, because you do not want to give it up. The Dutch boy and the dyke is so satisfying that the Netherlands built a statue to a fictional child. Knowing why a falsehood sticks — because it flatters us, comforts us, or simply tells well — is half the work of resisting it.

Key takeaways

Mental model

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Practical application

Notice when you want the myth to be true

The sober-up myths survive on hope: nobody wants the answer to be "just wait." When a belief offers a convenient escape — a shortcut, a rescue, a flattering trait — treat your own desire as a warning light, not as support.

Test the demonstration that "proves" it

Diamond merchants smashed real diamonds to convince miners the stones were fake — exploiting a myth on purpose. A dramatic act can be staged, selective, or simply misread. Ask what would happen if you ran the test honestly and completely.

Separate affection from accuracy

People believe good things about dogs because they love dogs. Loving something does not improve its mouth bacteria. Keep your fondness and your facts in separate columns.

Example

A driver has had two drinks, feels the room sharpen after a strong coffee, and decides they are fine to drive. The coffee did nothing to the alcohol — it only cancelled the drowsiness, leaving a fully impaired driver who now feels alert. That is the most dangerous version of a wishful myth: it does not just fail to help, it removes the warning sign. The honest move is to wait, or hand over the keys.

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