Ever find yourself in a situation where you suddenly realise how much you don't know? How many unknown unknowns are out there, waiting to surprise you?

These phrases, popularised by former US Secretary of Defence Donald Rumsfeld, have been around for centuries. As it turns out, acknowledging the unknown has been an important part of human progress.

Let's take a journey through the origins of these thought-provoking concepts. From ancient Persia to modern politics, understanding known knowns, known unknowns, unknown knowns and unknown unknowns can give us a more humble and realistic view of the world.

What we know is vast, but dwarfed by what we don't know and can't even conceive of yet. Rather than seeing uncertainty and ignorance as weakness, we can choose to embrace the unknown unknowns in life with a sense of possibility. Who knows what wonders and adventures await, just out of sight, waiting to be discovered? The unknown may be unsettling, but it contains infinite potential too.

gray concrete statue on green grass during daytime
Photo by Stefano Vigorelli / Unsplash

The Origins of Knowns and Unknowns in Ancient Persia

The origins of the phrases 'known knowns', 'known unknowns' and 'unknown unknowns' date back to ancient Persia. Philosophers discussed the idea that there were things in life that were known and understood, things that were known but not fully grasped, and things that were unknown and hidden from our understanding.

Centuries later, former US Secretary of Defence Donald Rumsfeld brought these terms into the mainstream. In a press conference about the Iraq war, he stated: "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."

Rumsfeld meant that when making decisions, especially in times of crisis, leaders have to grapple with these different types of knowledge and uncertainty. The 'known knowns' are things that are known and understood. The 'known unknowns' are risks and uncertainties that are recognised and can be managed to some extent.

But the 'unknown unknowns' are the most dangerous - they are uncertainties that are not yet recognised or understood. Because we don't know they exist, we can't foresee or plan for them. All we can do is try to identify them as soon as possible, and adapt quickly.

For individuals, recognising these different types of knowledge and uncertainty can help in decision making, risk management and avoiding ignorance or overconfidence. The more we can turn 'unknown unknowns' into 'known unknowns' or even 'known knowns', the better informed and prepared we will be to face challenges in life. But we must always keep exploring, questioning and learning - because there will always be unknowns left to discover.

The Rediscovery of Knowns and Unknowns in the 20th Century

Have you ever stopped to think about what you know and what you don’t know?

This idea has origins dating back to ancient Persia, recognising our knowledge has limits. As human understanding progresses, the ‘known unknowns’ shift into ‘known knowns’, but what lies beyond remains uncertain.

The 20th Century Rediscovery

In the early 20th century, this concept re-emerged. The rapid pace of scientific discovery revealed how much was unknown. Thinkers like Socrates and Confucius advocated accepting the limits of one’s knowledge.

  • Known knowns: facts, information, skills, and experiences you have and are aware of. The earth revolves around the sun. 2+2=4. How to tie your shoelaces.
  • Known unknowns: uncertainties and questions you have contemplated. The origins of the universe. Whether there is life after death. How to play the piano.
  • Unknown knowns: knowledge and skills you have but are unaware of. Speaking a language fluently but not realising it. Having a hidden talent. Unconscious biases and beliefs.
  • Unknown unknowns: the unpredictable surprises. Black swan events. Emerging technologies. Pandemics. Things beyond our imagination.

By acknowledging the limitations of human knowledge, we open our minds to discovery. What unknown joys and insights await beyond the horizon? The more we explore, the more our known knowns may grow—but so too the unknowns beyond. Such is the introspective journey into the knowns and unknowns.

white duck with yellow beak
Photo by Hussain Badshah / Unsplash

Donald Rumsfeld and the Knowns and Unknowns of the Iraq War

Donald Rumsfeld, the Secretary of Defence under George W. Bush, famously spoke of “known knowns,” “known unknowns,” and “unknown unknowns” in reference to the Iraq War. This phrase has endured and spread into popular culture, though its origins go back much further.

Known Knowns

The idea of categorising knowledge into knowns and unknowns dates back centuries. In the 1300s, Persian philosopher Al-Ghazali wrote of the four types of knowledge: known knowns, known unknowns, unknown knowns, and unknown unknowns. The “known knowns” refer to things we know we know—our core base of knowledge and facts. For Rumsfeld and the Iraq War, the known knowns were the intelligence they had about Iraq’s weapons programmes.

Known Unknowns

The “known unknowns” are things we know we don't know—uncertainties and questions we have identified. Rumsfeld cited the known unknowns as the uncertainties inherent with any military operation. We know there are things we don't fully understand, like how Saddam Hussein would react or what conditions allied forces would face. The known unknowns represent risks and uncertainties that come with any complex situation.

Unknown Unknowns

The most dangerous are the “unknown unknowns”—things we don't know we don't know. These hidden risks and unforeseen events can derail even the best-laid plans. For the Iraq War, the unknown unknowns were ultimately realities like the strength of the insurgency, the challenges of occupation, and the descent into sectarian conflict. The unknown unknowns highlight why humility and caution are so important in any ambitious endeavour.

Rumsfeld’s articulation of these concepts struck a chord because it highlights fundamental truths about knowledge, planning, and risk. We can never escape uncertainty and surprise, no matter how much we know. The unknown unknowns will always be out there, waiting to emerge in unexpected ways. By acknowledging this reality, we can make wiser choices and anticipate at least some of the hidden bumps in the road ahead.

white ceramic mug in flat lay photography
Photo by Flemming Fuchs / Unsplash

What We Know and What We Don't Know in Our Daily Lives

In our daily lives, there are many things we know, things we know we don’t know, and things we don’t even know we don’t know. Understanding this concept can help us avoid overconfidence in our knowledge and make better decisions.

What We Know

These are facts, events or ideas that we are consciously aware of and understand based on evidence and experience. For example, you know that the sky is blue, the earth revolves around the sun, your best friend’s name, or the capital of France. Known knowns form the basis of our reality and shape how we view the world.

What We Know We Don’t Know

These are gaps in our knowledge that we recognise and can identify. Things like what really happens inside a black hole, will there be a cure for cancer in our lifetime or who will win the next World Cup. We know we lack information or insight into these areas, so we can explore them through research, questioning and discovery.

What We Don't Know We Don't Know

This category represents unknown unknowns - things that we don't even realise we lack information or awareness about. These hidden gaps in our knowledge can catch us by surprise and lead to mistakes or poor decision-making if left unexamined.

Understanding these three types of knowledge - or lack thereof - helps create humility and openness. We can seek to expand the known knowns through constant learning and experience. We can work to reduce known unknowns through research, study and experimentation. But we must also try to uncover hidden unknown unknowns through critical thinking, diverse input and challenging our assumptions. Complete knowledge may always elude us, but we can strive to make the unknown known, and the unseen seen.

a statue of a couple hugging each other
Photo by Marcel Ardivan / Unsplash

Embracing the Unknown Unknowns - Things We Don't Know We Don't Know

The unknown unknowns are humbling because they remind us of the limits of human knowledge and control. No matter how clever or prepared we are, there are always uncertainties beyond our imagination. This is an unsettling thought for most. We prefer to believe the world is knowable and controllable.

Yet there is freedom in accepting our ignorance. We can stop chasing the illusion of total knowledge and embrace life's unpredictability. The unknown unknowns, as alarming as they seem, make life endlessly interesting. They are the source of surprise, wonder, and mystery.

Rather than viewing unknown unknowns as threats, we might see them as opportunities. They push us outside our routines and certainties, forcing us to improvise, adapt, and grow. Like any unknown, they hold the potential for both danger and possibility. Our approach determines which we experience. With an open and curious mindset, the unknown unknowns enrich our journey rather than derail it.

In the end, the unknown unknowns remind us to cultivate humility, flexibility, and openness. These qualities, more than any amount of knowledge, prepare us for whatever life brings next. The unknown unknowns will continue arising, so we better get used to them!


The truth is, the more we know, the more we realise how much we don't know. Life is full of uncertainties and unpredictables, and accepting that fact is a crucial part of growth and wisdom.

Rather than fretting over the unknowns, focus on expanding your known-knowns through continuous learning and experiences. At the same time, keep an open and curious mind about the known-unknowns and unknown-unknowns - you never know what life-changing discoveries or opportunities they may hold! The key is finding the right balance between gaining knowledge and staying humble in the face of uncertainty. Keep exploring, keep learning, keep living. The journey is as important as the destination.