A Commonplace Book

Dark archives are the repositories of human knowledge to which we no longer have operational access. They are the documents that have been lost, even though they still exist and the records that hold information we don't realize is there.

Mr. Rumsfeld has become, in a way, our patron saint.

You may recall that in the wake of the decision to conduct a retaliatory invasion of Iraq in 2002, Mr. Rumsfeld infamously tried to explain the problems around planning for war. "There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know."

Known knowns. Known unknowns. Unknown unknowns.

If you think about that formulation, you'll see that there is an unspoken fourth quadrant. These are the unknown knowns: the things we don't know that we know.