
"There are unknown unknowns" is a phrase from a response
United States Secretary of Defense
The United States secretary of defense (acronym: SecDef) is the head of the United States Department of Defense (DoD), the United States federal executive departments, executive department of the United States Armed Forces, U.S. Armed Forces, a ...
Donald Rumsfeld
Donald Henry Rumsfeld (July 9, 1932 – June 29, 2021) was an American politician, businessman, and naval officer who served as United States Secretary of Defense, secretary of defense from 1975 to 1977 under President Gerald Ford, and again ...
gave to a question at a
U.S. Department of Defense (DoD) news briefing on February 12, 2002, about the lack of evidence linking the government of
Iraq
Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and ...
with the supply of
weapons of mass destruction
A weapon of mass destruction (WMD) is a Biological agent, biological, chemical weapon, chemical, Radiological weapon, radiological, nuclear weapon, nuclear, or any other weapon that can kill or significantly harm many people or cause great dam ...
to terrorist groups.
Rumsfeld stated:
The statement became the subject of much commentary. In ''The Decision Book'' (2013), author refers to it as the "Rumsfeld matrix". The statement also features in a 2013 documentary film, ''
The Unknown Known'', directed by
Errol Morris.
Known unknowns refers to "risks you are aware of, such as canceled flights",
whereas unknown unknowns are risks that come from situations that are so unexpected that they would not be considered.
With respect to awareness and understanding, unknown unknowns can be compared to other types of problems in the following matrix:
Origins
Rumsfeld's statement brought attention to the concepts of known knowns, known unknowns, and unknown unknowns, but these were in common use in US defense procurement by the late 1960s.
In a 1968 study sponsored by the Aerospace Industries Association, Hudson Drake from North American Rockwell argued that defence contractors had to solve both known unknowns and "unanticipated unknowns".
Also in 1968, Lt. Gen. William B. Bunker noted that when developing complex weapons systems "there are two kinds of technical problems: there are the known unknowns, and the unknown unknowns."
The usage was common enough for an industry shorthand to have developed where unknown-unknowns were referred to as "unk-unks".
The term was commonly used inside
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
. Rumsfeld cited
NASA administrator William Graham in his memoir; he wrote that he had first heard "a variant of the phrase" from Graham when they served together on the
during the late 1990s.
Rumsfeld had previously publicly used the terms himself, stating in a 2000 speech that "There are known knowns, known unknowns and unknown unknowns. Effective intelligence work must consider them all."
The terms "known unknowns" and "unknown unknowns" are often used in
project management
Project management is the process of supervising the work of a Project team, team to achieve all project goals within the given constraints. This information is usually described in project initiation documentation, project documentation, crea ...
and
strategic planning
Strategic planning is the activity undertaken by an organization through which it seeks to define its future direction and makes decisions such as resource allocation aimed at achieving its intended goals. "Strategy" has many definitions, but it ...
circles.
Contemporary usage is largely consistent with the earliest known usages. For example, the term was used in evidence given to the British Columbia Royal Commission of Inquiry into Uranium Mining in 1979:
The term also appeared in a 1982 ''
New Yorker'' article on the
aerospace industry
Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial, and military applications. Aerospace engineering consists of aeronautics and astr ...
, which cites the example of
metal fatigue
In materials science, fatigue is the initiation and propagation of cracks in a material due to cyclic loading. Once a fatigue crack has initiated, it grows a small amount with each loading cycle, typically producing striation (fatigue), striati ...
, the cause of crashes in
de Havilland Comet
The de Havilland DH.106 Comet is the world's first commercial jet airliner. Developed and manufactured by de Havilland in the United Kingdom, the Comet 1 prototype first flew in 1949. It features an aerodynamically clean design with four ...
airliners in the 1950s.
Reaction
Canadian columnist
Mark Steyn
Mark Steyn () is a Canadian author and a radio, television, and on-line presenter. He has written several books, including The New York Times Best Seller list, ''The New York Times'' bestsellers ''America Alone'', ''After America (Steyn book), A ...
called it "in fact a brilliant distillation of quite a complex matter".
Australian economist and blogger
John Quiggin wrote: "Although the language may be tortured, the basic point is both valid and important."
Psychoanalytic philosopher
Slavoj Žižek
Slavoj Žižek ( ; ; born 21 March 1949) is a Slovenian Marxist philosopher, cultural theorist and public intellectual.
He is the international director of the Birkbeck Institute for the Humanities at the University of London, Global Distin ...
says that beyond these three categories there is a fourth, the unknown known, that which one intentionally refuses to acknowledge that one knows: "If Rumsfeld thinks that the main dangers in the confrontation with Iraq were the 'unknown unknowns', that is, the threats from Saddam whose nature we cannot even suspect, then the
Abu Ghraib scandal shows that the main dangers lie in the "unknown knowns"—the disavowed beliefs, suppositions and obscene practices we pretend not to know about, even though they form the background of our public values."
German sociologists Christopher Daase and Oliver Kessler agreed that the
cognitive frame for political practice may be determined by the relationship between "what we know, what we do not know, what we cannot know", but stated that Rumsfeld left out "what we do not like to know".
The event has been used in multiple books to discuss
risk assessment
Risk assessment is a process for identifying hazards, potential (future) events which may negatively impact on individuals, assets, and/or the environment because of those hazards, their likelihood and consequences, and actions which can mitigate ...
.
Rumsfeld named his 2011 autobiography ''
Known and Unknown: A Memoir''. In the author's note at the start of the book, he expressly acknowledges the source of his memoir's title and mentions a few examples of his statement's prominence.
''
The Unknown Known'' is the title of
Errol Morris's 2013 biographical documentary film about Rumsfeld. In it, Rumsfeld initially defines "unknown knowns" as "the things you think you know, that it turns out you did not", and toward the end of the film he defines the term as "things that you know, that you don't know you know".
Rumsfeld's comment earned the 2003
Foot in Mouth Award from the British
Plain English Campaign.
Historical context
As alluded to by Rumsfeld in his autobiography, over two millenia ago
Socrates
Socrates (; ; – 399 BC) was a Ancient Greek philosophy, Greek philosopher from Classical Athens, Athens who is credited as the founder of Western philosophy and as among the first moral philosophers of the Ethics, ethical tradition ...
considered known unknowns and unknown unknowns.
Much later,
Thomas Aquinas
Thomas Aquinas ( ; ; – 7 March 1274) was an Italian Dominican Order, Dominican friar and Catholic priest, priest, the foremost Scholasticism, Scholastic thinker, as well as one of the most influential philosophers and theologians in the W ...
in his
Summa Theologica
The ''Summa Theologiae'' or ''Summa Theologica'' (), often referred to simply as the ''Summa'', is the best-known work of Thomas Aquinas (1225–1274), a scholastic theologian and Doctor of the Church. It is a compendium of all of the main t ...
also emphasized the important difference between recognized ignorance and unconscious ignorance.
Rumsfeld's statement closely parallelled a
well-known proverb about knowledge:
This has been widely quoted since the 19th century as (for example) an anonymous
Persian,
Arabic,
African,
Japanese,
Oriental
or simply an old proverb, or
attributed to authors ranging from
Confucius
Confucius (; pinyin: ; ; ), born Kong Qiu (), was a Chinese philosopher of the Spring and Autumn period who is traditionally considered the paragon of Chinese sages. Much of the shared cultural heritage of the Sinosphere originates in the phil ...
to
Bruce Lee
Bruce Lee (born Lee Jun-fan; November 27, 1940 – July 20, 1973) was an American-born Hong Kong martial artist, actor, filmmaker, and philosopher. He was the founder of Jeet Kune Do, a hybrid martial arts philosophy which was formed from ...
.
The proverb is actually a close translation (with line order reversed) of
al-Khalil ibn Ahmad al-Farahidi
Abu ‘Abd ar-Raḥmān al-Khalīl ibn Aḥmad ibn ‘Amr ibn Tammām al-Farāhīdī al-Azdī al-Yaḥmadī (; 718 – 786 CE), known as al-Farāhīdī, or al-Khalīl, was an Arab philologist, lexicographer and leading grammarian of Basra in ...
's medieval epigram about the "four kinds of men", as reported by
Al-Ghazali
Al-Ghazali ( – 19 December 1111), archaically Latinized as Algazelus, was a Shafi'i Sunni Muslim scholar and polymath. He is known as one of the most prominent and influential jurisconsults, legal theoreticians, muftis, philosophers, the ...
(1058-1111 CE),
which was later echoed in poems by
Nasir al-Din al-Tusi
Muḥammad ibn Muḥammad ibn al-Ḥasan al-Ṭūsī (1201 – 1274), also known as Naṣīr al-Dīn al-Ṭūsī (; ) or simply as (al-)Tusi, was a Persians, Persian polymath, architect, Early Islamic philosophy, philosopher, Islamic medicine, phy ...
and
Ibn Yamin.
"Unknown unknowns" were occasionally mentioned in the 1950s and 60s.
In 1950, it was noted that sociology research was full of "unknown unknowns". In a 1962 commencement address, Nobel laureate biochemist
Melvin Calvin discussed how humanity "must grapple not only with the known and the 'known unknown', but also with the vastness of the 'unknown unknown'."
A related 2x2 grid was created in 1955 by two American psychologists, Joseph Luft and Harrington Ingham in their development of the
Johari window, a "graphic model of interpersonal behaviour" that classifies knowledge about your behavior and motivations in terms of whether you or others are aware of those behaviours or motivations. For example, your motivation might be (un)known by you and (un)known by others.
Another similar classification scheme is the
conscious competence learning model published in 1960, where a person's knowledge and skills are classified according to how (un)conscious and (in)competent they are.
Analytical sciences
The term "known unknowns" has been applied to the identification of chemical substances using
analytical chemistry
Analytical skill, Analytical chemistry studies and uses instruments and methods to Separation process, separate, identify, and Quantification (science), quantify matter. In practice, separation, identification or quantification may constitute t ...
approaches, specifically
mass spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used ...
. In many cases, an unknown to an investigator that is detected in an experiment is actually known in the chemical literature, a reference database, or an Internet resource. These types of compounds are termed "known unknowns". The term was originally coined by Little et al. and reported a number of times in the literature since then as a general approach.
See also
*
Black swan theory
*
Cynefin framework
*
Dunning–Kruger effect
The Dunning–Kruger effect is a cognitive bias in which people with limited competence in a particular domain overestimate their abilities. It was first described by the psychologists David Dunning and Justin Kruger in 1999. Some researcher ...
*
Emic and etic
In anthropology, folkloristics, linguistics, and the social and behavioral sciences, ''emic'' () and ''etic'' () refer to two kinds of field research done and viewpoints obtained.
The ''emic'' approach is an insider's perspective, which loo ...
*
Epistemic modal logic
*
Four stages of competence
*
I know that I know nothing
"I know that I know nothing" is a saying derived from Plato's account of the Greek philosopher Socrates: ''"For I was conscious that I knew practically nothing..."'' (Plato, Apology 22d, translated by Harold North Fowler, 1966). It is also someti ...
*
Ignoramus et ignorabimus
*
Ignotum per ignotius
''Ignotum per ignotius'' (Latin for "the unknown by the more unknown") describes an explanation that is less familiar than the concept it would explain.
An example would be: "The oven felt hot because of Fourier's law." It is unlikely that a pers ...
*
Johari window
*
Knightian uncertainty
In economics, Knightian uncertainty is a lack of any quantifiable knowledge about some possible occurrence, as opposed to the presence of quantifiable risk (e.g., that in statistical noise or a parameter's confidence interval). The concept acknow ...
* ''
Known and Unknown: A Memoir''
*
Outside Context Problem
*
Russell's teapot
*
Undecidable problem
In computability theory and computational complexity theory, an undecidable problem is a decision problem for which it is proved to be impossible to construct an algorithm that always leads to a correct yes-or-no answer. The halting problem is an ...
* ''
The Unknown Known''
*
Wild card (foresight)
*
Argument from ignorance
Argument from ignorance (), or appeal to ignorance, is an informal fallacy where something is claimed to be true or false because of a lack of evidence to the contrary.
The fallacy is committed when one asserts that a proposition is true because ...
References
External links
*
*
{{Iraq War
American phraseology
Epistemology
Political quotes
Unknown content
Ignorance
2002 quotations
Donald Rumsfeld
Iraq War terminology