קאווע שטיבל

קוואוטס פון אמאליגע און היינטיגע צוגלייך, איבער אלעס און אלעמען. איך הייב אן מיט א היינטיגן.

There are known knowns; there are things we know that we know"
known unknowns; that is to say there are things that, we now know we don't know
"But there are also unknown unknowns – there are things we do not know we don't know
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United States Secretary of Defense, Donald Rumsfeld

http://en.wikipedia.org/wiki/There_are_known_knowns

http://www.youtube.com/watch?v=vIJUIWUYLVg