Overview
Occam's Razor says that when several explanations account for the same evidence, the one with the fewest assumptions is usually the best starting point. It isn't a law that the simplest answer is always right — it's a guide to where to look first, because each added assumption is another thing that could be wrong.
The model saves you from over-elaborate theories when a plain one will do, while leaving room for complexity when the evidence genuinely demands it.
When to use it
Choosing between competing explanations for something.
How to apply it
List the explanations
Lay out the competing theories that could account for the facts.
Count the assumptions
See which explanations require the most unproven leaps.
Prefer the simplest that fits
Start with the one that explains the evidence with the fewest assumptions.
Add complexity only if needed
Reach for a more elaborate theory only when the simple one fails to fit.
Common pitfalls
- Treating 'simplest' as 'always correct' rather than 'check first'.
- Over-simplifying genuinely complex situations to force a tidy answer.
- Confusing 'fewest assumptions' with 'least effort to imagine'.
Frequently asked questions
Does Occam's Razor prove the simple answer is right?
No — it's a heuristic for where to look first. The simplest explanation that fits the facts is the best starting hypothesis, not a guarantee.
When should I ignore it?
When the evidence genuinely requires a more complex explanation — simplicity yields to fit, not the other way around.