Eliminating the impossible: This is probably the most famous of Sherlockian quotations. It appears in six different adventures in slightly different format:

1. Eliminate all other factors, and the one which remains must be the truth. (SIGN)
2. How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth? (SIGN)
3. It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (BERY)
4. When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth. (BLAN)
5. We must fall back upon the old axiom that when all other contingencies fail, whatever remains, however improbable, must be the truth. (BRUC)
6. It is impossible as I state it, and therefore I must in some respect have stated it wrong. (PRIO)
7. Improbable as it is, all other explanations are more improbable still. (SILV)