Named for William of Ockham (Summa Logicae, c. 1323), though the principle of parsimony is older than he is.
Prefers the explanation that needs the fewest added assumptions when competing explanations fit the evidence equally well.
When to reach for it
Several explanations for a problem fit the facts, and an elaborate story is winning over a simpler one.
How it runs
- List the candidate explanations.
- List the assumptions each one needs.
- Adopt the one with the fewest that still fits the evidence.
- Drop it as soon as evidence demands more.
- Resist adding patches to rescue a favorite.
Where it sits in SOLVE eX
Go to the source
- Summa Logicae, c. 1323