TL;DR
A philosophical razor is a tool used to eliminate improbable options in a given situation. Occam’s razor is used to solve problems more quickly and efficiently.
- Summary: among competing hypotheses, the one with the fewest assumptions should be selected. The simplest explanation is preferable to one that is more complex.
- Used to help make rapid decisions and establish truths without empirical evidence. It works best as a mental model for making initial conclusions before the full scope of information can be obtained.
Examples:
- In science: when you have two competing theories that make exactly the same predictions, the simpler one is better.
- In medicine: look for the fewest possible causes to explain their patient’s multiple symptoms, and give preference to the most likely causes. “When you hear hoofbeats, think horses, not zebras.”
Exceptions and Issues
- The simpler explanation, although having a higher chance of being correct, is not always true.
- Use it carefully, especially when it comes to important or risky decisions. When you hear hoofbeats behind you, in most cases you should think horses, not zebras—unless you are out on the African savannah.