On February 12, 2002, then Secretary of Defense, Donald Rumsfeld, famously stated:
Reports that say that something hasn’t happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don’t know we don’t know. And if one looks throughout the history of our country and other free countries, it is the latter category that tend to be the difficult ones.
Lawyers tend to focus on the known unknowns––thus, our fixation with pretrial investigation and discovery. We believe that if only we can secure a few more vital pieces of information, we can successfully resolve the case. We therefore focus on filling those gaps in our knowledge we know exist. This is a reasonable, and widely utilized, method; it’s also incomplete.
During litigation, what about those areas we don’t know we don’t know? These are by far the largest, shrouded in secrecy, covered in darkness. Hypothesis, guess, conjecture––we can postulate but we can never be sure. In one sense, one’s ability to detect, discover, and explore these areas distinguishes the most accomplished from the rest. The ability to see around corners, look through walls––the uncanny ability to know when something exists though it cannot be seen.
During his press conference, Secretary Rumsfeld did not discuss a potential fourth category; that is, that of the unknown knowns. Is there such a category? There is. It’s the category of things we don’t know we know. This may seem a bit self-contradictory, but it’s not. This category would encompass things we once knew but have forgotten. It would also include things we once knew but 
are now incapable of recognizing. The unknown knowns are actually a rather important component of our perception of reality.
Things we once knew but have forgotten. Childhood presents to us a rain of visual and sensory impressions which we have to make sense of and put into context. Much of what we know is buried deep in our subconscious, outside of our ability to recollect or retrieve. Without this massive, mixed, and multi-layered web of insights and perceptions we would not be who we are.
Things we once knew but are now incapable of recognizing. Aging causes us to change. We not only act differently, but we see and perceive things differently as well. As we age, we come to see some things more distinctly; others, less. There are certain things we no longer recognize as we get older, but they still influence our take on reality.
Take, for example, our relationships with people, our reactions to events, or our values and beliefs. We reach stages in our life where we no longer hold precisely the same view of these as we did when we were younger. At times, with the best of intentions, our view of the world can become myopic, self-deceiving.
Lawyers should know of this category of the unknown knowns. In questioning a witness, it’s useful to ask: what are the things we don’t know we know? What’s buried underneath? What best explains what has occurred? What was once known by this witness but is now incapable of being recognized? The other three categories, of course, have their role as well, but this particular category may lead to areas of questioning which might otherwise be neglected.
Lawsuits can be safely generalized as knowledge conflicts, battles in epistemology. It’s not enough to ask what’s missing––we should ask as well what’s present, but unseen.
