Occam's Razor

What it means

Occam’s Razor is the principle that, when you have competing explanations for something, the one that makes the fewest assumptions is most likely correct. It doesn’t guarantee the simplest answer is always right - sometimes reality is genuinely complicated. But as a starting point for investigation, simplicity is a remarkably reliable guide.

Named after William of Ockham, a 14th-century friar, the idea isn’t about dumbing things down. It’s about not adding complexity you don’t need. If your keys are missing, the explanation “I put them down somewhere and forgot” requires fewer assumptions than “someone broke in, took only my keys, and left everything else untouched.”

The razor is especially useful as a defence against conspiracy thinking. Conspiracy theories almost always require a vast number of people to be perfectly coordinated, perfectly silent, and perfectly competent - a set of assumptions that, on their own, should raise serious doubts.

In the real world

In science, Occam’s Razor is a foundational principle. When two theories explain the same data equally well, scientists prefer the one with fewer assumptions - not because nature is always simple, but because unnecessary complexity adds unnecessary opportunities to be wrong.

In everyday life, it’s a useful check on overthinking. If a friend hasn’t replied to your message, Occam’s Razor suggests they’re busy - not that they’re angry, avoiding you, or sending a deliberate signal. The simplest explanation is almost always the healthiest one to start with.