Occam's Razor
Between competing explanations, the one requiring the fewest assumptions is usually the better bet. Simplicity makes an idea easier to test and trust, though it's no guarantee that reality will actually cooperate.
Occam’s razor is usually summarized as “don’t multiply entities beyond necessity” — the idea that between two explanations that both fit the facts, the one relying on fewer assumptions deserves the benefit of the doubt. It’s named for the 14th-century philosopher William of Ockham, though the phrase itself is a later paraphrase of his broader argument for parsimony in reasoning.
Why the Simpler Explanation Wins
Every extra assumption an explanation requires is another place it can be wrong. An explanation with five independent conditions that all have to hold is far more fragile than one with a single condition — even if each individual condition seems plausible on its own, the odds of all five holding simultaneously drop fast. Preferring the simpler explanation isn’t about aesthetics; it’s about not building a theory on more load-bearing assumptions than the evidence actually requires.
Examples
Technical Issues: If a computer won’t turn on, a loose power cable is a far more likely culprit than a catastrophic hardware failure — both explanations fit the symptom, but one requires far less to be true.
Natural Phenomena: Strange noises at night are more plausibly a settling house or a small animal than anything paranormal — the mundane explanation asks for less from the world than the exotic one does.
Where It Breaks Down
Occam’s razor is a heuristic for which hypothesis to test first, not proof that the simple one is correct. Reality is sometimes genuinely complicated, and the simplest available explanation is occasionally just wrong. The razor tells you where to start looking, not where to stop.
The Broader Lesson
Munger’s own approach to worldly wisdom was to build a lattice of the best models from every discipline — physics, biology, psychology, and philosophy among them. Occam’s razor is one of philosophy’s clearest contributions to that lattice: a general-purpose check against explanations that have grown more elaborate than the evidence demands.
Sources
- ”Do not multiply entities beyond necessity” is a later Latin formulation (non sunt multiplicanda entia sine necessitate), not a direct quotation of William of Ockham (c. 1287–1347); it paraphrases his repeated arguments for parsimony