The Hedgehog and the Fox

How to think and change your mind

When I first read Philip Tetlock’s Superforecasting, I thought I understood his concept of “the fox knows many things, but the hedgehog knows one big thing.". It sounds right, you don’t need to dig deeper, do you?

It is the basis of another famous principle: “Strong assumptions, weakly held.”

I am sure you heard it many times, and it felt like a great quote. But think about it one second: can you explain to someone what it actually means?

When I read this fabulous essay by Venkatesh Rao, who wrote some of the best essays I ever read, I understood I did not really understand those concepts. I had been guilty of the illusion of understanding bias.

In this piece, I explain these ideas by synthesising and expanding on Venkatesh’s essay, The Cactus and the Weasel.

Both Hedgehogs and Foxes actually know many things

The Fox draws his decision-making principles and mental models from many independent data points in various fields. He bases his thinking on universal concepts he grew familiar with over time, such as entropy, marginal return/utility, stable/unstable equilibria, etc. Those are weak assumptions, because they are narrow concepts that apply only in principle to different situations, but he can afford to hold them strongly, because they have the incredible benefit to having held true in all fields he has encountered them so far.

But the Hedgehog also knows many things. The difference is that they are mostly focused on a single domain of expertise. It can be investing, religion, or politics. The Hedgehog holds those convictions strongly, because they are his domain.

How Hedgehogs and Foxes change their mind

Since Hedgehogs have a strong (narrow) set of strong values/convictions, they need to accept that they are to hold those weakly if they do not want to fall into dogma and/or fanaticism. To Hedgehogs, changing their mind amounts to a paradigm shift. It implies a full pivot. It is tough.

Foxes, however, can afford holding their weaker (distributed) convictions strongly since none of them individually takes too much importance in shaping their thinking process. To Foxes, changing their means replacing one brick from their thinking-pattern foundation with another - hopefully better - one. It is much easier, but far less visible and impactful.

How Hedgehogs and Foxes compare in real life

Hedgehogs tend to be doers and leaders. Foxes tend to be thinkers and strategists. (It does not mean one can teach himself how to thrive on the other side.)

Hedgehogs gain their efficiency from good habits. Foxes are more comfortable leading their life in abstraction and metacognition.

Hedgehogs risk being dogmatic. Foxes are more flexible.

Hedgehogs change their mind suddenly and in bulk (a tipping-point mechanism). Foxes change their mind slowly and very progressively.

Hedgehogs are great at standardization. Foxes are great at pattern-recognition.

As Venkatesh puts it: Hedgehogs are local-bullshit-resistant: a master salesman will feel your weakness in sales from miles away. Foxes are general-bullshit-resistant: they might not be an expert in your field, but if one of your underlying assumptions violates one of their many proven mental models, they will flag it and root it out. (I can’t count the number of times I’ve been in that last situation - crazy someone has not killed me yet.)

Debating with a Hedgehog feels like pushing against a tractor. Debating with a Fox feels like pushing against an Aikido master.


Hedgehogs experience fragile metacognition (their system can get really wrong because of one bad conviction/value), but antifragile doing (their habits and convictions will keep them going and acting). Hedgehogs will reach a destination, but it might be wrong by a mile.

Foxes experience antifragile metacognition (their system cannot get that wrong because of their breadth of hypotheses, and gets reinforced by each new divergent input), but fragile doing (they can easily fall into overanalysis, excessive doubt, and action paralysis). Foxes might be fast in reaching a clear-cut destination, but it won’t be wrong by much. This is the whole thesis of Philip Tetlock’s Superforecasting.


Hedgehogs risk falling into cognition-without-metacognition: pure dogma, no critical thinking.

Foxes risk falling into metacognition-without-cognition: trying to generalise lots things they don’t really understand.

Both are really bad.

A more specific risk is for young Foxes being exposed to old Hedgehogs. Thinking the old Hedgehog was as careful in building his mental models as they - young Foxes - are, young Foxes might accept old Hedgehogs strong and loud convictions as a given, and build their own mental models on top of it. We then end up with a broad and strongly-held foundation built on a castle of cards: really dangerous.

The most extreme danger for Hedgehogs is fanaticism. On this subject, I warmly recommend one of the most brilliant human psychology books I have ever read: Eric Hoffer’s The True Believer. In chapter 13, he says: “We can [only] be absolutely certain about [ideas] we do not fully understand.” - this is the danger archetype for Hedgehogs.

Real-life examples

Socrates was a fox. Plato was combining bad traits of both.

Warren Buffett is a fox. Napoleon was a hedgehog.

Elon Musk is probably a super-mutant.

Google is a fox. Apple is a hedgehog. In everything: vision, organisation, products, etc.

Applying the concept to organisations and nations

Apple is the example of the success Fox. Apple knows one thing: how to consistently make a beautiful user experience loved by a specific market segment. It does not care about risk diversification. It does not care about diversified innovation. It does not care much about customers who do not fit their typical user. It knows one thing, and it does it outstandingly well - for a tremendous profit.

Google is the exact opposite: a true Fox. It incubates a tremendous amount of products, fosters intrapreneurship, and generally addresses an incredibly large set of human problems… quite well. It is a smart and successful Fox though: it kills least promising products and knows how to choose which weak assumptions to hold strongly.

Those are not conflicting truth: those two distinct - and equally successful - strategies simply reflect the founder/leader’s preference and own thinking process. That is why Steve Jobs would always tell Larry Page: “You’re doing too much stuff”, to which the latter would answer: “You’re not doing enough stuff.”

Regarding nations, I am coming back to Eric Hoffer’s The True Believer. In one of the brilliant pieces of thinking in his book, he explains the evolution of mass movements over time. In chapter 17, he details:

"A movement is pioneered by men of words, materialized by fanatics and consolidated by men of action. It is usually an advantage to a movement, and perhaps a prerequisite for its endurance, that these roles should be played by different men succeeding each other as conditions require. When the same person or persons (or the same type of person) leads a movement from its inception to maturity, it usually ends in disaster."


"The genuine man of action is not a man of faith but a man of law." [...] "The man of action is eclectic in the methods he uses to endow the new order with stability and permanence."

Disruptive change is lead by Hedgehogs, but the realm of incremental innovation and productive processes is governed by Foxes.

As Hoffer pertinently points out, it is incredibly rare that the same individual can excel at both.


If you know yourself, you can leverage your strength, work on your biases, and consistently maximise your chances of success.

That’s why whether you are a Hedgehog or a Fox, Socrates will always be right.