What Are Our Known Knowns?
Much of our life is spent learning things. At school, with books, with people, at the job, etc. But what does it mean to really know something, and how much can it really be accomplished?
I’m a big fan of Donald Rumsfeld’s famous quote:
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.
This of course applies to a lot more than just matters of state.
The unknown unknowns are pretty scary. But just naming them, identifying them, even in the broadest sense possible, helps us feel like they’re getting a bit closer to the “known unknowns” category.
There are giant territories in the known unknown category when you consider the sum of human knowledge: consciousness, quantum mechanics, the limits of the universe, the origin of life, etc. And, individually, there are much more mundane things, unique to each of us: the contents of others’ minds, what’s happening on the other side of that wall, how your friend makes their special recipe, all the things we learned once and then forgot.
But I think even in the “known known” category, we have plenty of things to worry about. What do we actually know and how certain can we be?
I’m also a big fan of Hume’s Fork, which states that there are only two categories of human knowledge: relations of ideas (ie. 2+2=4, a cat is a kind of mammal, bicycles usually have two wheels, an apple is the fruit of an apple tree, etc), and matters of fact (the sun rises in the morning, apples fall down from their trees, cats love to sleep, etc).
All of the knowledge in the “relations of ideas” camp is true by definition. They’re abstract concepts that can be proven by their definitions, because they have no form or meaning outside of their definitions.
All of the knowledge in the “matters of fact” camp can never be proven. They can describe how things behaved in the past but there’s no certainty that the future will continue to behave like the past.
In other words, the fact that “known unknowns” and “unknown unknowns” exist mean that we can never really be certain of the “known knowns”. One of those unknowns could change all the rules about how our knowns have been working.
Another way to think of it is that we can’t know anything unless we know everything.
Until then, an apple is part knowable (as far as it maps to relations of ideas) and part unknowable (everything else about it).
An apple is just a part of a tree, which is part of a plants/bugs/soil/water/air/sunlight system. Each of the parts of that system belong to much larger systems (the carbon cycle pulling carbon atoms from the air by using light-powered photosynthesis), the billions of years old systems of photons and stars and galaxies that make photosynthesis possible, the death of stars that generated more complex atoms in the first place, natural selection over millions of years that created life patterns and plant patterns and apple tree patterns in the first place, plus everything else in the universe and multiverse).
Does knowing what an apple is require us to know all of that? Seems like we’d have to if we wanted to fully understand an apple through and through.
But all of that isn’t required if the pre-requisite of knowledge is just that it be useful.
Maybe all we need to know about an apple is that it is tasty, and healthy. Maybe also that it is red (easy to find), and fairly easy to grow (reliable). At that level, it’s valuable for us to keep this in mind and use the info in our day-to-day.
This puts apples much closer to the “known unknown” camp. Maybe we don’t know apples, or anything, at all. We just have heuristics for how to label and use “known unknowns” to give us some survival advantage.
A known unknown is something we can identify/recognize, give a name for future reference, and may or may not fit into some category of usefulness. As “matters of fact” there’s no guarantee that those names and uses will continue in the future, but we can then give it a new name and a new use.
My stop is here! Bye!
— written on BART
