Deductive Reasoning - Eliminate the Impossible
When you have eliminated the impossible, whatever remains, however improbable, must be the truth.
“When you have eliminated the impossible, whatever remains, however improbable, must be the truth.”
- Sherlock Holmes (Arthur Conan Doyle), The Sign of Four
Systematically rule out what cannot be true; what remains must be the answer, even if it seems unlikely.
The Method
- Gather all possibilities
- Eliminate the impossible using facts and logic
- Accept what remains (verify when possible)
Why This Works
- Forces systematic thinking, preventing jumping to conclusions
- Handles unlikely truths we might otherwise dismiss
- Builds confidence through rigorous elimination
Limitations
- Requires discrete, finite possibilities
- Needs clear criteria for “impossible”
- Remaining answer may still need verification
Related Concepts
- [[Primary Sources in Historical Research]] - Using evidence to eliminate possibilities
- [[Source: Eliminate the Impossible]]
Source: [[Eliminate the Impossible - Sherlock Holmes]]
4 notes link here
- Design of Experiments (DoE) A formal way to design a task that explains the variation under conditions.
- Inversion Looking at a problem or decision from the opposite point of view to avoid …
- Primary Sources in Historical Research The importance of primary sources - firsthand accounts from people who were …
- Eliminate the Impossible - Sherlock Holmes Sherlock Holmes's principle of deductive reasoning - eliminate the impossible.