KNOWN KNOWNS.

The message is:
That there are known knowns,
there are things we know that we know.
There are 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,
and each year we discover a few more,
of those unknown unknowns.

—Feb. 12, 2002, Department of Defense news briefing

email Known Knowns

Add yourself to the Known Knowns Frappr map