And of course there’s Donald Rumsfeld, he of the unknown unknown. I’m thinking here of a third category beyond his “known unknown” and “unknown unknown”: the unknowable unknown.
Even though it’s easy enough to think about not knowing, as I’m doing now, it’s not something I do very often. I seldom look at the wall of a lecture theater and realize that I don’t know what’s behind it. My thinking stops at the wall, and bounces back into the room that I can perceive.
Dogs are largely oblivious to human conversation. They don’t follow the to and fro of conversation. They are aware of the sound and some if its import, but they don’t know its meaning. In a sense, it doesn’t exist for them. In the same way, I’m ignorant of much going on inside me and around me, and I’m ignorant of the fact that I’m ignorant.
Things I know sometimes feel like places. As I learn more about a subject, I can begin to assemble the rooms representing topics into a building. But if I don’t know something (statistics, say) it’s not as if it’s the unexplored south wing of a mansion. There is no south wing. I have no sense of its shape. Something once known but now forgotten (like Green functions, in my case) are ghostly ruins remembered from a dream; there are only wisps and fragments.
We make up stuff to hide the fact that we don’t know. Helen Phillips describes in New Scientist (“Mind fiction: Why your brain tells tall tales,” 7 October 2006) how people make up stories when the reasons for their action are not available to conscious introspection:
[Timothy Wilson and Richard Nisbett] laid out a display of four identical items of clothing and asked people to pick which they thought was the best quality. It is known that people tend to subconsciously prefer the rightmost object in a sequence if given no other choice criteria, and sure enough about four out of five participants did favour the garment on the right. Yet when asked why they made the choice they did, nobody gave position as a reason. It was always about the fineness of the weave, richer colour or superior texture. This suggests that while we may make our decisions subconsciously, we rationalise them in our consciousness, and the way we do so may be pure fiction, or confabulation.
Note that people didn’t say, “I don’t know.” This is an important result for the study of hard intangibles. We are usually not aware that we have a limitation. Sometimes cannot even believe that we’re limited. Here’s another excerpt from the New Scientist story:
It is surprisingly common for stroke patients with paralysed limbs or even blindness to deny they have anything wrong with them, even if only for a couple of days after the event. They often make up elaborate tales to explain away their problems. One of Hirstein's patients, for example, had a paralysed arm, but believed it was normal, telling him that the dead arm lying in the bed beside her was not in fact her own. When he pointed out her wedding ring, she said with horror that someone had taken it. When asked to prove her arm was fine, by moving it, she made up an excuse about her arthritis being painful. It seems amazing that she could believe such an impossible story. Yet when Vilayanur Ramachandran of the University of California, San Diego, offered cash to patients with this kind of delusion, promising higher rewards for tasks they couldn't possibly do - such as clapping or changing a light bulb - and lower rewards for tasks they ould, they would always attempt the high pay-off task, as if they genuinely had no idea they would fail.
If we can observe the limitation in others, we can at least study it, if not experience it ourselves. However, it will be hard to teach others – and ourselves – to behave differently if, in our bones, we still cannot conceive of our lack.