A Study in Scarlet (Sherlock Holmes, #1)

by Arthur Conan Doyle

Now the skilful workman is very careful indeed as to what he takes into his brain-attic.

Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.”

“It is a capital mistake to theorize before you have all the evidence. It biases the judgment.”

“What you do in this world is a matter of no consequence,” returned my companion, bitterly. “The question is, what can you make people believe that you have done.