Rumsfeld’s Logic of Known Knowns, Known Unknowns and Unknown Unknowns
By: Paul Austin Murphy
Tags: Known Unknowns, Knowledge, Donald Rumsfeld, Logic, Unknown Unknowns

On February the 12th, 2002, the then Secretary of Defense of the United States, Donald Rumsfeld, stated the following words (as captured in a YouTube video here):

“[A]s 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.”

At first I wasn’t going to tackle this passage because some people may believe that I have some political sympathy for Donald Rumsfeld and what he said. However, since this passage was spoken some 18 years ago, and was spoken by someone who no longer has a prominent position in politics, I can’t see why that should be the case. Besides which, I shan't refer to the political context of Rumsfeld’s words at all (although I will offer a little background). Indeed I shall take his words as a short piece of logic and epistemology.

So it may seem odd — or perverse — too see these words as Rumsfeld’s attempt at logic and epistemology!… Actually, I don’t see it that way — at least not entirely.

In terms of at least a little context. Rumsfeld’s words were a response to a question about the lack of evidence linking Saddam Hussein’s regime in Iraq to the supply of “weapons of mass destruction” to various terrorist groups.

The passage above is almost always taken to be gobbledegook and/or political dissimulation. They were even awarded the Foot in Mouth Award. (Read the BBC on this here.) Indeed I’ve vague recollections of interpreting his words as political dissimulation and prevarication the first time I heard them.

Rumsfeld himself said that “the logic” of his words might have seemed “obscure” and “enigmatic”. Rumsfeld also mentioned Socrates:

“Some with an interest in philosophy have made note of a line attributed to Socrates: ‘I neither know nor think that I know.’ This has been interpreted to mean that the beginning of wisdom is the realization of how little one truly knows.”

Interestingly enough, even the Slovenian philosopher Slavoj Žižek couldn’t resist making exclusively political sense of Rumsfeld’s words. I mean that in the sense that Žižek didn’t really say anything about the purely logical force of the passage. (See Žižek’s article — from 2004 — here.) Of course there was no reason to take Rumsfeld’s words as being purely — and innocently — logical! That’s obviously the case. Then again, Žižek himself did — kinda — recognise the logic of Rumsfeld’s statements. That said, Žižek simply connected Rumsfeld’s logic to political deceit and hypocrisy. More specifically, Žižek happily accepted that there were “unknown unknowns” when it came to Saddam Hussein’s regime. However, although Žižek accepted Rumsfeld’s unknown unknowns, he also stressed the known knowns. (Žižek had the torture at Abu Ghraib in mind here.)

Having put Žižek’s negative response, there were also positive responses from some people. And, by that, I don’t mean positive responses which were purely motivated by politics. (They were political too.) For example, Mark Steyn called Rumsfeld’s words “a brilliant distillation of quite a complex matter”. In addition, Australian economist John Quiggin stated that “[a]lthough the language may be tortured, the basic point is both valid and important”.

I would simply say that the logic and epistemology underlying Rumsfeld’s words couldn’t help but be “tortured” — as my own commentary will show!

In any case, Rumsfeld’s words weren’t entirely original anyway. For example, the phrases “known unknowns” and “unknown unknowns” had already been used in strategic planning and project management. It can also be seen that they date back to 1997 (see here). (The phrase “known unknowns” has been used to refer to “risks you are aware of, such as cancelled flights”.) Rumsfeld himself wrote:

“I first heard a variant of the phrase ‘known unknowns’ in a discussion with former NASA administrator William R. Graham, when we served together on the Ballistic Missile Threat Commission in the late 1990s.”

Indeed my bet is that these phrases can probably be found many times before the 1990s. And, as I’ll attempt to show, they’ve also been featured many times in logic and philosophy — even if not in the precise way in which Rumsfeld expressed them!

But what of Rumsfeld’s peculiar way of expressing them?

The main reason that Rumsfeld’s words were seen as gobbledegook (rather than as pure political dissimulation) was the repeated use of the word “know” and its derivatives. That is, we have such phrases as “know knowns”, “know we know”, “known unknowns” and “unknown unknowns”. However, this is very similar to such well-known phrases as “love to love”, “the death of death”, “the end of the end”, “truer than true”, “bigger than big”, “life in life”, etc.

Again, at first glance, Rumsfeld’s words seem to either be gobbledegook or political dissimulation — or both! Yet they also make logical sense. This means that his words may be logical and an expression of (context-based) political dissimulation at one and the same time! Added to that is the fact that Rumsfeld’s words are… well, somewhat poetic. Indeed they’re almost like a Zen koan.

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So let’s simplify Donald Rumsfeld’s words:

As we know,

1) There are known knowns.

There are things we know we know.

2) We also know there are some things we do not know.

3) But there are also unknown unknowns -

The ones we don’t know we don’t know.

And all the above can be pared down further in this way:

(1) known knowns

(2) known unknowns

(3) unknown unknowns

Now let’s take one statement at a time:

(1) Known Knowns

Rumsfeld said that “[k]nown knowns are facts, rules, and laws that we know with certainty”. For example, “[w]e know [that] gravity is what makes an object fall to the ground”.

(1) is actually fairly problematic. It immediately hints at a possible infinite regress which has be found many times in various parts of philosophy.

Let me explain.

If we know p, and also know that we know p, then do we also need to know that we know that we know p? (This is very Rumsfeldian in tone.) And so on. What’s more, if we can stop at knowing that we know p (i.e., we don’t need to concern ourselves with knowing that we know that we know p), then perhaps we can also cut this regress short by simply settling for knowing p. Again, why do we also need to know that we know p?

At a more basic level, we can provisionally accept that there are “known knowns”. Generally, people accept that we know that we know that, say, the sun is the center of the solar system. But, again, what does knowing that we know p add to simply knowing p? What is it, exactly, to know that we know any given p?

In addition, if there can be “known knowns”, then what sense can we make of subject S not knowing that he knows p? That is, can S know p without also knowing that he knows p? If S can know p without also knowing that he knows p, then the opening clause “knowing that” (in “knowing that I know p”) may be redundant. In other words, why not stick with “S knows p”?

This is somewhat like an epistemic version of the redundancy theory of truth.

Take this compound sentence:

The sentence “Snow is white” is true.

Some philosophers have argued that the clause “is true” is “redundant”. (It may still have pragmatic force.) Similarly, in the sentence

“I know that I know that snow is white.”

the clause “I know that” may also be redundant. (Perhaps that too only has pragmatic force.)

Something similar to this epistemic regress is found in logic.

Take Lewis Carrol’s premises paradox.

In this paradox the sceptic demands a justification of the premises which lead to a specific conclusion (i.e., in a logical argument). More tellingly, the sceptic also requires a justification of the inferential links between the premises themselves, not just a justification of the premises.

Yet if such justifications were given of the premises, then these justifications would also need justifications too. Indeed this would also apply to the justifications of the links between the premises and between all the premises and the conclusion. And then those justifications would themselves require their own higher-order justifications.

The solution to this (as with simply accepting the statement “S knows that p”) is simply to argue that the way the premises lead to a conclusion simply doesn’t need a justification. All justifications are contained within the terms and statements used in the argument; as well as in the “logical rules” implicitly used. In other words, the logical argument must stand on its own if we’re to avoid an infinite regress.

(2) Known Unknowns

Rumsfeld stated that “[k]nown unknowns are gaps in our knowledge, but they are gaps that we know exist”. He continued:

“If we ask the right questions we can potentially fill this gap in our knowledge, eventually making it a known known.”

This makes sense at the same time as being problematic.

For example, we know that there are aspects of distant galaxies that we don’t know anything about. More mundanely, we know that we don’t know how many grains of sand there are on Earth. (Surely there must be an exact number.) We also know that we don’t know how many times King Henry VIII farted in his entire lifetime. (He must have farted a given number of times in his lifetime.)

However, there’s something odd about knowing that we don’t know any given x. In order to know that we don’t know about any given x, we must at least know something about that x in order to so much as mention it. We don’t know, then, the exact number of grains of sands on the Earth (or how many times King Henry VIII farted in his lifetime); but we do know that there must be a specific number.

This means that talking about “unknowns” is fine. However, also talking about “known unknowns” is problematic.

On a different tack.

The British philosopher Colin McGinn strongly claims that we will never know certain “deep truths” about consciousness (see here). But how does he know that? How does McGinn know that we will never know these deep truth about consciousness? Surely, in order to know that we don’t know anything about any given x, then that implies that we must at least know something about that given x. Of course it’s true that knowing something about x isn’t the same as knowing everything about x. However, we still know something about x. And if we know something about x, then how can we rule out our knowing everything — or at least much more — about x? So, in McGinn’s case, there are indeed (to go back to Rumsfeld’s words) “some things we do not know” about consciousness. However, can we also conclude that we will never know the deep truths about consciousness?

(3) Unknown Unknowns

Rumsfeld says that the “category of unknown unknowns is the most difficult to grasp”. Moreover, “[t]hey are gaps in our knowledge, but gaps that we don’t know exist”. He continued:

“There are many things of which we are completely unaware — in fact, there are things of which we are so unaware, we don’t even know we are unaware of them.”

Surely it’s a little problematic to say that there is a “gap[] in our knowledge” if, ostensibly, we don’t know anything about that gap or even anything about the subject of that gap. Technically, a human subject can neither know nor not know something about that which he doesn’t know about. More prosaically, a subject can’t have a position on some subject he’s never even heard of. Perhaps such an epistemic situation can’t even be described as being a lack of knowledge in that there are infinite things which any given subject will not — and cannot — know about. So, again, this is hardly an epistemological deficit.

(3) above is also Rumsfeld’s cute distinction between our not knowing about (to use my earlier examples) the supposed deep truths of consciousness, how many grains of sand there are on Earth, and how many times King Henry VIII farted in his lifetime, and our not knowing about things we don’t even know we don’t know about. (Here again things are getting very Rumsfeldian.) In Rumsfeld’s own words, these are “things of which we are so unaware, we don’t even know we are unaware of them”.

In these cases of unknown unknowns, it’s simply impossible to give any examples. No examples can be given of things we know we don’t know about. That’s because if any examples were given, then that would betray the fact that we — at the least — know something about the things we don’t know everything about. However, in Rumsfeld’s case, we’re supposed to be talking about “unknown unknowns”. That is, things “we don’t know we don’t know”.

So can’t we ask how we know that there are some things “we do not know”? To know that there are unknowns in any given area (or even unknown generally) hints at the fact that we are at the least (metaphorically) on the periphery of those unknowns. In other words, what are these unknown things we’re referring to?

So is this situation a little like Plato’s beard?

In the Plato’s beard analogy (as expressed by W.V.O Quine), the argument (at its most basic) is that the very mention of some x which is supposed not to exist confers some kind of “being” on it. Thus Pegasus, nothing and even the round square must have some kind of being. Why? Because we refer to these… things.

So if we use Plato’s beard and reapply it (if in a loose way) to this logical and epistemological case, then the very mention of unknown unknowns hints that we at least know that these things are unknown — therefore we know at least one thing about them. (Socrates knew at least one thing — that he “knew nothing”.)

To sum up.

It’s not that we need to know the things we don’t know because then we’d know them. However, do we know that (to get back to Rumsfeld’s words) “there are some things we do not know”? It is very likely that we don’t know many things. However, do we also know that we don’t know many things? How could we know that? To repeat: it’s highly probable that we don’t know many things. However, can we also know that we don’t know many things?