It is a capital mistake to theorize before one has data. The Adventures of Sherlock Holmes
14. If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle. The Art Of War
The man of knowledge must be able not only to love his enemies but also to hate his friends. Ecce Homo
Because learning does not consist only of knowing what we must or we can do, but also of knowing what we could do and perhaps should not do. The Name of The Rose
Quotes