Derek Sivers

Programmer, writer, avid student of life. I make useful things, and share what I learn.
Antifragile - by Nassim Nicholas Taleb

Antifragile - by Nassim Nicholas Taleb

Go to the Amazon page for details and reviews.

Bold perspectives, unusual ideas, and surprisingly wise advice around an interesting subject of the “opposite of fragile.” Looking through that lens at health, education, governments, business, and life philosophy. Very inspiring, and sparks a lot of further discussion.

my notes

Some things thrive and grow when exposed to volatility, randomness, disorder, and stressors: evolution, culture, ideas, revolutions, political systems, technological innovation, bacterial resistance.

Hydra has numerous heads. Each time one is cut off, two grow back. So harm is what it likes. Hydra represents antifragility.

Anything that has more upside than downside from random events (or certain shocks) is antifragile.

Things are antifragile up to a certain level of stress. Your body benefits from some amount of mishandling, but only up to a point.

“It builds character.”

We are largely better at doing than we are at thinking.

We want to survive uncertainty and have the last word. But how to domesticate, even dominate, even conquer, the unseen, the opaque, and the inexplicable?

I’d rather be dumb and antifragile than extremely smart and fragile.

Many modern ailments seem to be associated with a lack of randomness in feeding and the absence of the stressor of occasional starvation.

The tragedy of modernity: as with neurotically overprotective parents, those trying to help are often hurting us the most.

We can live happily in a world we don’t understand.

Don't confuse rationalizing with rational - the two are almost always exact opposites.

Policies and actions in which the benefits are small and visible, and the side effects potentially severe and invisible.

The medical fragilista overintervenes in denying the body’s natural ability to heal and gives you medications with potentially very severe side effects.

Trenchant prose: no skill to understand it, mastery to write it.

Heuristics are simplified rules of thumb that make things simple and easy to implement. But their main advantage is that the user knows that they are not perfect, just expedient.

Black Swans dominate society and history (and people, because of ex post rationalization, think themselves capable of understanding them). As a consequence, we don’t quite know what’s going on, particularly under severe nonlinearities.

It does not mean that one’s personal experiences constitute a sufficient sample to derive a conclusion about an idea; it is just that one’s personal experience gives the stamp of authenticity and sincerity of opinion.

Being nice to the arrogant is no better than being arrogant toward the nice.

George Santayana: "A man is morally free when he judges the world, and judges other men, with uncompromising sincerity."

Commerce is fun, thrilling, lively, and natural. Academia is none of these.

Only academics and other non-real-world operators use the expression “real-world solution” instead of simply “solution.”

The fragile wants tranquility, the antifragile grows from disorder, and the robust doesn’t care.

Debt always fragilizes economic systems.

I have an obsessive stance against government indebtedness.

Book: "Through the Language Glass" by linguist Guy Deutscher

Humans somehow fail to recognize situations outside the contexts in which they usually learn about them.

How do you innovate? First, try to get in trouble. Innovation sparks from initial situations of necessity, in ways that go far beyond the satisfaction of such necessity. The excess energy released from overreaction to setbacks is what innovates!

Moderns try today to create inventions from situations of comfort, safety, and predictability instead of accepting the notion that “necessity really is the mother of invention.”

Cato looked at comfort as a road to waste.

The automation of airplanes is making flying dangerously comfortable, dulling the pilot’s attention from too little challenge.

“The albatross’s giant wings prevent him from walking”

If tired, go to the gym for some exertion instead of resting.

Most humans squander their free time, as free time makes them dysfunctional, lazy, and unmotivated.

Have enough self-control to make the audience work hard to listen.

Layers of redundancy are the central risk management property of natural systems.

Redundancy is opportunistic, so such extra strength can be used to some benefit even in the absence of the hazard.

What they call “inefficient” is often very efficient.

Antifragile passion.

Information is antifragile; it feeds more on attempts to harm it than it does on efforts to promote it. Many wreck their reputations merely by trying to defend it.

Fire feeds on obstacles.

Criticism for a book is a truthful, unfaked badge of attention, signaling that it is not boring.

Smear campaigns, if you can survive them, help enormously, conditional on the person appearing to be extremely motivated and adequately angry.

To detect the independence and robustness of someone’s reputation: those who dress outrageously are robust or even antifragile in reputation; those clean-shaven types who dress in suits and ties are fragile to information about them.

It is only when you don’t care about your reputation that you tend to have a good one.

Those from whom we have benefited the most aren’t those who have tried to help us (say with “advice”) but rather those who have actively tried - but eventually failed - to harm us.

Machines are harmed by low-level stressors (material fatigue), organisms are harmed by the absence of low-level stressors (hormesis).

Humans eventually wear out (hopefully leaving their genes, books, or some other information behind.

Much of aging comes from a misunderstanding of the effect of comfort - a disease of civilization.

Society, economic activities and markets, and cultural behavior are apparently man-made but grow on their own to reach some kind of self-organization. They may not be strictly biological, but they resemble the biological in that, in a way, they multiply and replicate - think of rumors, ideas, technologies, and businesses. They are closer to the cat than to the washing machine but tend to be mistaken for washing machines.

Your bones will get weaker if you spend a lot of time riding a bicycle.

Humans tend to do better with acute than with chronic stressors, particularly when the former are followed by ample time for recovery, which allows the stressors to do their jobs as messengers.

You pick up a language best from error to error, when you need to communicate under straining circumstances, situational difficulty, being forced to read the mind of the other person - suspending one’s fear of making mistakes.

Touristification castrates by sucking randomness out - converting activities into a script.

Writing is only worth it when it provides us with the tingling effect of adventure.

An environment with variability does not expose us to chronic stress injury.

If you walk on uneven, not man-made terrain, no two steps will ever be identical.

The fragility of every startup is necessary for the economy to be antifragile.

Another business example: Restaurants are fragile; they compete with each other, but the collective of local restaurants is antifragile for that very reason. Had restaurants been individually robust, hence immortal, the overall business would be weak, and would deliver nothing better than cafeteria food.

So some parts on the inside of a system may be required to be fragile in order to make the system antifragile as a result.

From the outside, it looks like there is hormesis, but from the inside, there are winners and losers.

Something hierarchically superior to that organism benefits from the damage.

When you starve yourself of food, it is the bad proteins that are broken down first and recycled by your own body - a process called autophagy.

It is often the mistakes of others that benefit the rest of us.

Had the Titanic not had that famous accident, we would have kept building larger and larger ocean liners and the next disaster would have been even more tragic. So the people who perished were sacrificed for the greater good; they unarguably saved more lives than were lost.

Every plane crash makes the next one less likely, but every bank crash makes the next one more likely.

Someone who has made plenty of errors - though never the same error more than once - is more reliable than someone who has never made any.

My characterization of a loser is someone who, after making a mistake, doesn’t introspect, doesn’t exploit it, feels embarrassed and defensive rather than enriched with a new piece of information, and tries to explain why he made the mistake rather than moving on. These types often consider themselves the “victims”.

Modern society should be treating ruined entrepreneurs in the same way we honor dead soldiers.

There is no such thing as a failed soldier, dead or alive (unless he acted in a cowardly manner) - likewise, there is no such thing as a failed entrepreneur or failed scientific researcher, any more than there is a successful babbler, philosophaster, commentator, consultant, lobbyist, or business school professor who does not take personal risks.

Avoidance of small mistakes makes the large ones more severe.

Switzerland is the most antifragile place on the planet; it benefits from shocks that take place in the rest of the world.

Switzerland is the last major country that is not a nation-state, but rather a collection of small municipalities left to their own devices.

Stability is achieved by managing noise, having a mechanism for letting it run its natural course, not by minimizing it.

Some people have fallen for the naive turkey-style belief that the world is getting safer and safer, and of course they naively attribute it to the holy “state” (though bottom-up Switzerland has about the lowest rate of violence of any place on the planet). It is exactly like saying that nuclear bombs are safer because they explode less often.

The European Union is legally protected from overcentralization thanks to the principle of subsidiarity: things should be handled by the smallest possible unit that can manage them with efficacy.

Small forest fires periodically cleanse the system of the most flammable material, so this does not have the opportunity to accumulate.

Buridan’s Donkey can be saved thanks to a random nudge.

Inject random noise into a system to improve its functioning.

Stochastic resonance, adding random noise to the background makes you hear the sounds (say, music) with more accuracy.

The ancients perfected the method of random draw situations - and integrated it into divinations. These draws were really meant to pick a random exit without having to make a decision, so one would not have to live with the burden of the consequences later. You went with what the gods told you to do, so you would not have to second-guess yourself later.

Medical error still currently kills between three times (as accepted by doctors) and ten times as many people as car accidents in the United States. It is generally accepted that harm from doctors - not including risks from hospital germs - accounts for more deaths than any single cancer.

Having a word for something helps spread awareness of it.

Capitalism is an inverse-iatrogenic effect, the unintended-but-not-so-unintended consequences: the system facilitates the conversion of selfish aims at the individual level into beneficial results for the collective.

Phenomenology is the observation of an empirical regularity without a visible theory for it.

Drachten, a town in the Netherlands, in which a dream experiment was conducted. All street signs were removed. The deregulation led to an increase in safety, confirming the antifragility of attention at work, how it is whetted by a sense of danger and responsibility.

Be careful not to overgeneralize the Drachten effect, as it does not imply the effectiveness of removing all rules from society.

It’s much easier to sell “Look what I did for you” than “Look what I avoided for you.” Of course a bonus system based on “performance” exacerbates the problem.

Procrastination is our natural defense, letting things take care of themselves and exercise their antifragility.

I defer the writing of a passage until my body tells me that I am ready for it.

I once procrastinated and kept delaying a spinal cord operation as a response to a back injury - and was completely cured of the back problem after a hiking vacation in the Alps, followed by weight-lifting sessions.

If I defer writing a section, it must be eliminated. This is simple ethics: Why should I try to fool people by writing about a subject for which I feel no natural drive?

Someone imperturbable, with the ability to be calm under fire that is considered necessary to become a leader, only reacts to real information. Someone of the type we call neurotic, largely to noise. The difference between the two fellows will show us the difference between noise and signal. Noise is what you are supposed to ignore, signal what you need to heed.

If you look at the very same data on a daily basis, the composition would change to 95 percent noise, 5 percent signal. And if you observe data on an hourly basis, as people immersed in the news and market price variations do, the split becomes 99.5 percent noise to 0.5 percent signal. That is two hundred times more noise than signal - which is why anyone who listens to news (except when very, very significant events take place) is one step below sucker.

There is so much noise coming from the media’s glorification of the anecdote.

We are separated from the real world. The media only report the most anecdotal and sensational cases (hurricanes, freak accidents, small plane crashes), giving us a more and more distorted map of real risks.

By presenting us with explanations and theories, the media induce an illusion of understanding the world.

The best way to mitigate interventionism is to ration the supply of information, as naturalistically as possible.

Famine in China that killed 30 million people between 1959 and 1961.

Next time someone in a suit and tie gave them projections for some dates in the future, they should ask him to show what he had projected in the past.

The robust and antifragile don’t have to have as accurate a comprehension of the world as the fragile - and they do not need forecasting.

Make things more robust to defects and forecast errors, or even exploit these errors, making lemonade out of the lemons.

Switch the blame from the inability to see an event coming. Not seeing a tsunami or an economic event coming is excusable; building something fragile to them is not.

We cannot afford to rely on the rationalistic elimination of greed and other human defects that fragilize society. Rather, make society benefit from the greed and other perceived defects of the human race.

The Swedish government’s focus on total fiscal responsibility after their budget troubles in 1991 - it makes them much less dependent on economic forecasts.

I suggest stocking up on novels, as we tend to underestimate the boredom of these long hours waiting for the trouble to dissipate. And books, being robust, are immune to power outages.

The worst thing one can do to feel one knows things a bit deeper is to try to go into them a bit deeper. The sea gets deeper as you go further into it.

To detouristify his traveling: he tried to inject some randomness into his schedule by never deciding on the next destination until he had spent some time in the first one. His next destination would be determined by his state of mind.

By betting against fragility, they were antifragile.

A man is honorable in proportion to the personal risks he takes for his opinion.

To avoid the charity trap, systematically making donations, but not to those who directly asked for gifts. And he never, never gave a penny to any charitable organization, with the possible exception of those in which not a single person earned a salary.

Fat Tony did not believe in predictions. But he made big bucks predicting that some people - the predictors - would go bust. Why? Someone who predicts will be fragile to prediction errors. An overconfident pilot will eventually crash the plane. And numerical prediction leads people to take more risks. Fat Tony is antifragile because he takes a mirror image of his fragile prey. Fat Tony’s model is quite simple. He identifies fragilities, makes a bet on the collapse of the fragile unit.

Seneca was the wealthiest person in the Roman Empire. He focused on the practical aspect of Stoicism: how to handle adversity and poverty and, even more critically, wealth.

To become a successful philosopher king, it is much better to start as a king than as a philosopher.

“I lost nothing,” after an adverse event. Stoicism makes you desire the challenge of a calamity. And Stoics look down on luxury.

He is in debt, whether he borrowed from another person or from fortune.

Stoicism: What we learn from reading Seneca directly, rather than through the commentators, is a different story. Seneca’s version of that Stoicism is antifragility from fate. No downside from Lady Fortuna, plenty of upside.

Success brings an asymmetry: you now have a lot more to lose than to gain. You are hence fragile.

When you become rich, the pain of losing your fortune exceeds the emotional gain of getting additional wealth.

Possessions make us worry about downside, thus acting as a punishment as we depend on them. All upside, no downside. Even more: dependence on circumstances - rather, the emotions that arise from circumstances - induces a form of slavery.

Seneca’s practical method to counter such fragility was to go through mental exercises to write off possessions, so when losses occurred he would not feel the sting - a way to wrest one’s freedom from circumstances. It is similar to buying an insurance contract against losses.

For my last job, I wrote my resignation letter before starting the new position, locked it up in a drawer, and felt free while I was there.

It is hard to stick to a good discipline of mental write-off when things are going well, yet that’s when one needs the discipline the most.

Stoicism is about the domestication, not necessarily the elimination, of emotions.

The modern Stoic sage is someone who transforms fear into prudence, pain into information, mistakes into initiation, and desire into undertaking.

Seneca proposes a complete training program to handle life and use emotions properly - thanks to small but effective tricks.

A catalogue of social deeds: invest in good actions. Things can be taken away from us - not good deeds and acts of virtue.

Simple test: if I have “nothing to lose” then it is all gain and I am antifragile. If you have less to lose than to gain, more upside than downside, then you like volatility and you are also antifragile.

A Stoic is a Buddhist with attitude, one who says “f*** you” to fate.

If you put 90 percent of your funds in boring cash (assuming you are protected from inflation) or something called a “numeraire repository of value,” and 10 percent in very risky, maximally risky, securities, you cannot possibly lose more than 10 percent, while you are exposed to massive upside.

Someone with 100 percent in so-called “medium” risk securities has a risk of total ruin from the miscomputation of risks.

A barbell can be any dual strategy composed of extremes, without the corruption of the middle - somehow they all result in favorable asymmetries.

Provide for the worst; the best can take care of itself. (Observe how people tend to provide for the best and hope that the worst will take care of itself.)

Take literature, that most uncompromising, most speculative, most demanding, and riskiest of all careers. There is a tradition with French and other European literary writers to look for a sinecure, say, the anxiety-free profession of civil servant, with few intellectual demands and high job security, the kind of low-risk job that ceases to exist when you leave the office, then spend their spare time writing, free to write whatever they want, under their own standards. There is a shockingly small number of academics among French authors. American writers, on the other hand, tend to become members of the media or academics, which makes them prisoners of a system and corrupts their writing, and, in the case of research academics, makes them live under continuous anxiety, pressures, and indeed, severe bastardization of the soul. Every line you write under someone else’s standards, like prostitution, kills a corresponding segment deep inside.

You can easily barbell yourself by removing the chances of ruin in any area. I am personally completely paranoid about certain risks, then very aggressive with others. The rules are: no smoking, no sugar (particularly fructose), no motorcycles, no bicycles in town or more generally outside a traffic-free area such as the Sahara desert, no mixing with the Eastern European mafias, and no getting on a plane not flown by a professional pilot.

Outside of these I can take all manner of professional and personal risks, particularly those in which there is no risk of terminal injury. In social policy, it consists in protecting the very weak and letting the strong do their job, rather than helping the middle class to consolidate its privileges.

The exercise regimen: going for the maximum weight one can lift, then nothing, compared to other alternatives that entail less intense but very long hours in the gym. This, supplemented with effortless long walks, constitutes an exercise barbell.

Talk to either undergraduate students, cab drivers, and gardeners or the highest caliber scholars; never to middling-but-career-conscious academics.

The barbell does not need to be in the form of investment in inflation-protected cash and the rest in speculative securities. Anything that removes the risk of ruin will get us to such a barbell.

So just as Stoicism is the domestication, not the elimination, of emotions, so is the barbell a domestication, not the elimination, of uncertainty.

The rational flâneur is someone who, unlike a tourist, makes a decision at every step to revise his schedule, so he can imbibe things based on new information. The flâneur is not a prisoner of a plan.

The opportunism of the flâneur is great in life and business - but not in personal life and matters that involve others. The opposite of opportunism in human relations is loyalty, a noble sentiment - but one that needs to be invested in the right places, that is, in human relations and moral commitments. The error of thinking you know exactly where you are going and assuming that you know today what your preferences will be tomorrow has an associated one.

Never ask people what they want, or where they want to go, or where they think they should go, or, worse, what they think they will desire tomorrow.

This ability to switch from a course of action is an option to change.

An option is what makes you antifragile and allows you to benefit from the positive side of uncertainty, without a corresponding serious harm from the negative side.

“F*** you money” - a sum large enough to get most, if not all, of the advantages of wealth (the most important one being independence and the ability to only occupy your mind with matters that interest you) but not its side effects, such as having to attend a black-tie charity event.

A vacation resort with the most options is more likely to provide you with the activity that satisfies your tastes, and the one with the narrowest choices is likely to fail. So you need less information, that is, less knowledge, about the resort with broader options.

The option: it does not care about the average outcome, only the favorable ones.

Your work and ideas are antifragile if instead of having one hundred percent of the people finding your mission acceptable or mildly commendable, you are better off having a high percentage of people disliking you and your message (even intensely), combined with a low percentage of extremely loyal and enthusiastic supporters.

The luxury goods industry - jewelry, watches, art, expensive apartments in fancy locations, does not care about the average.

Growth in society may not come from raising the average the Asian way, but from increasing the number of people in the “tails,” that small, very small number of risk takers crazy enough to have ideas of their own.

Those endowed with that very rare ability called imagination, that rarer quality called courage, and who make things happen.

You don’t have to be right that often. All you need is the wisdom to not do unintelligent things to hurt yourself and recognize favorable outcomes when they occur.

Steve Jobs at a famous speech: “Stay hungry, stay foolish.” He probably meant “Be crazy but retain the rationality of choosing the upper bound when you see it.”

Any trial and error can be seen as the expression of an option, so long as one is capable of identifying a favorable result and exploiting it.

In trial and error, the rationality consists in not rejecting something that is markedly better than what you had before.

“Life is long gamma.” means “benefits from volatility and variability.”

All those brilliant minds who go to faraway conferences to discuss Gödel had to carry their suitcases through airport terminals, without thinking about applying their brain to such an insignificant transportation problem.

Great geniuses invent their predecessors.

Governments and universities have done very, very little for innovation and discovery, precisely because they look for the complicated, the lurid, the newsworthy, the narrated, the scientistic, and the grandiose, rarely for the wheel on the suitcase.

People with too much smoke and complicated tricks and methods in their brains start missing elementary, very elementary things.

Activity strips things to their simplest possible model.

Antifragile risk taking - not education and formal, organized research - is largely responsible for innovation and growth.

Practitioners don’t write; they do. Birds fly and those who lecture them are the ones who write their story. So it is easy to see that history is truly written by losers with time on their hands and a protected academic position.

Knowledge formation, even when theoretical, takes time, some boredom, and the freedom that comes from having another occupation, therefore allowing one to escape the journalistic-style pressure of modern publish-and-perish academia to produce cosmetic knowledge.

Since the winner will have an explosive payoff, uncapped, the right approach requires a certain style of blind funding. It means the right policy would be what is called “one divided by n” or “1/N” style, spreading attempts in as large a number of trials as possible: if you face n options, invest in all of them in equal amounts. 5 Small amounts per trial, lots of trials, broader than you want. Why? Because in Extremistan, it is more important to be in something in a small amount than to miss it. As one venture capitalist told me: “The payoff can be so large that you can’t afford not to be in everything.”

Knowledge in complex domains inhibits research. Studying the chemical composition of ingredients will make you neither a better cook nor a more expert taster - it might even make you worse at both.

Since you cannot forecast collaborations and cannot direct them, you cannot see where the world is going. All you can do is create an environment that facilitates these collaborations, and lay the foundation for prosperity.

Planning: it makes the corporation option-blind, as it gets locked into a non-opportunistic course of action.

Coca-Cola began as a pharmaceutical product. Tiffany & Co., the fancy jewelry store company, started life as a stationery store. The last two examples are close, perhaps, but consider next: Raytheon, which made the first missile guidance system, was a refrigerator maker (one of the founders was no other than Vannevar Bush, who conceived the teleological linear model of science we saw earlier; go figure). Now, worse: Nokia, who used to be the top mobile phone maker, began as a paper mill (at some stage they were into rubber shoes). DuPont, now famous for Teflon nonstick cooking pans, Corian countertops, and the durable fabric Kevlar, actually started out as an explosives company. Avon, the cosmetics company, started out in door-to-door book sales.

When engaging in tinkering, you incur a lot of small losses, then once in a while you find something rather significant. Such methodology will show nasty attributes when seen from the outside.

Under positive asymmetries, that is, the antifragile case, the “unseen” is positive. So “empirical evidence” tends to miss positive events and underestimate the total benefits.

Those who teach at Harvard should be expected to have much less understanding of things than cab drivers or people innocent of canned methods of inference.

(i) Look for optionality; in fact, rank things according to optionality
(ii) preferably with open-ended, not closed-ended, payoffs
(iii) Do not invest in business plans but in people, so look for someone capable of changing six or seven times over his career
(iv) Make sure you are barbelled, whatever that means in your business.

The doers have not written a lot of books. Their memory has been treated very badly by history. Formal thinkers and theorizing theorizers tend to write books; seat-of-the-pants people tend to be practitioners who are often content to get the excitement, make or lose the money, and discourse at the pub. Their experiences are often formalized by academics; indeed, history has been written by those who want you to believe that reasoning has a monopoly or near monopoly on the production of knowledge.

Formalists, to protect their turf, have always played on the logical fallacy that if quacks are found among nonacademics, nonacademics are all quacks.

Seeing the nontransferability of skills from one domain to the other led me to skepticism in general about whatever skills are acquired in a classroom.

What is picked up in the classroom stays largely in the classroom.

Those who play blind chess games with an entire cohort can’t remember things outside the board better than a regular person.

The biologist and intellectual E. O. Wilson was once asked what represented the most hindrance to the development of children; his answer was the soccer mom. They repress children’s natural biophilia, their love of living things. Soccer moms try to eliminate the trial and error, the nerds - that is, they are like computers except slower. Further, they are now totally untrained to handle ambiguity.

One can be an intellectual without being a nerd, provided one has a private library instead of a classroom, and spends time as an aimless (but rational) flâneur benefiting from what randomness can give us inside and outside the library. Provided we have the right type of rigor, we need randomness, mess, adventures, uncertainty, self-discovery, near-traumatic episodes, all these things that make life worth living, compared to the structured, fake, and ineffective.

Only the autodidacts are free.

Erudites and businessmen, people whose position did not depend on credentials.

My reading hours: between thirty and sixty a week, a practice I’ve kept up for a long time.

I was getting humiliated by people who started smoking me with complicated math. So I read almost every book with “probability” or “stochastic” in its title. I read nothing else for a couple of years. I was hungry to go deeper into the problem of small probabilities.

Find a problem first, and figure out the math that works for it.

Much of what other people know isn’t worth knowing.

The most severe mistake made in life is to mistake the unintelligible for the unintelligent.

Socrates’ technique was to make his interlocutor, who started with a thesis, agree to a series of statements, then proceed to show him how the statements he agreed to are inconsistent with the original thesis, thus establishing that he has no clue as to what he was taking about. Socrates used it mostly to show people how lacking in clarity they were in their thoughts, how little they knew about the concepts they used routinely - and the need for philosophy to elucidate these concepts.

He never lets the other person frame the question.

An answer is planted in every question.

Never respond with a straight answer to a question that makes no sense to you.

Logic excludes - by definition - nuances, and since truth resides exclusively in the nuances, it is “a useless instrument for finding Truth in the moral and political sciences.”

For Tony, the distinction in life isn’t True or False, but rather sucker or nonsucker. Things are always simpler with him.

Exposure is more important than knowledge.

Focus on the payoff from your actions instead of studying the structure of the world. The payoff, what happens to you (the benefits or harm from it), is always the most important thing, not the event itself.

You decide principally based on fragility, not probability.

We check people for weapons before they board the plane. Do we believe that they are terrorists: True or False? False, as they are not likely to be terrorists (a tiny probability). But we check them nevertheless because we are fragile to terrorism. There is an asymmetry. We are interested in the payoff, and the consequence, or payoff, of the True (that they turn out to be terrorists) is too large and the costs of checking are too low. Do you think the nuclear reactor is likely to explode in the next year? False. Yet you want to behave as if it were True and spend millions on additional safety, because we are fragile to nuclear events.

Modify your exposure and learn to get out of trouble.

I do not make appointments (other than lectures) except the very same morning, as a date on the calendar makes me feel like a prisoner.

In spite of what is studied in business schools concerning “economies of scale,” size hurts you at times of stress; it is not a good idea to be large during difficult times.

The hidden harm of fragility is that you need to be much, much better than random in your prediction and knowing where you are going, just to offset the negative effect.

If you have favorable asymmetries, or positive convexity, options being a special case, then in the long run you will do reasonably well, outperforming the average in the presence of uncertainty. The more uncertainty, the more role for optionality to kick in, and the more you will outperform. This property is very central to life.

It is the negative that’s used by the pros, those selected by evolution: chess grandmasters usually win by not losing; people become rich by not going bust.

The learning of life is about what to avoid. You reduce most of your personal risks of accident thanks to a small number of measures.

When it comes to knowledge, the same applies. The greatest - and most robust - contribution to knowledge consists in removing what we think is wrong - subtractive epistemology. In life, antifragility is reached by not being a sucker.

Since one small observation can disprove a statement, while millions can hardly confirm it, disconfirmation is more rigorous than confirmation.

Keeping one’s distance from an ignorant person is equivalent to keeping company with a wise man.

Steve Jobs: “People think focus means saying yes to the thing you’ve got to focus on. But that’s not what it means at all. It means saying no to the hundred other good ideas that there are. You have to pick carefully. I’m actually as proud of the things we haven’t done as the things I have done. Innovation is saying no to 1,000 things.”

We are moving into the far more uneven distribution of 99/1 across many things that used to be 80/20.

Almost everything contemporary has winner-take-all effects, which includes sources of harm and benefits.

A small number of employees in a corporation cause the most problems, corrupt the general attitude - and vice versa - so getting rid of these is a great solution.

More data - such as paying attention to the eye colors of the people around when crossing the street - can make you miss the big truck. When you cross the street, you remove data, anything but the essential threat.

If you have more than one reason to do something, just don’t do it. By invoking more than one reason you are trying to convince yourself to do something. Obvious decisions (robust to error) require no more than a single reason.

Antifragility implies - contrary to initial instinct - that the old is superior to the new, and much more than you think. No matter how something looks to your intellectual machinery, or how well or poorly it narrates, time will know more about its fragilities and break it when necessary.

What survives must be good at serving some (mostly hidden) purpose that time can see but our eyes and logical faculties can’t capture.

Prophet, follow the Fat Tony method of focusing on shekels more than recognition.

Technothinkers have autistic tendencies.

Lack of charm, interest in objects instead of persons, causing them to neglect their looks. They love precision at the expense of applicability. And they typically share an absence of literary culture. This absence of literary culture is actually a marker of future blindness because it is usually accompanied by a denigration of history.

To understand the future, you just need some respect for the past, some curiosity about the historical record, a hunger for the wisdom of the elders, and a grasp of the notion of “heuristics,” these often unwritten rules of thumb that are so determining of survival.

You will be forced to give weight to things that have been around, things that have survived.

Technology is at its best when it is invisible. When it displaces the deleterious, unnatural, alienating, and, most of all, inherently fragile preceding technology.

For the perishable, every additional day in its life translates into a shorter additional life expectancy. For the nonperishable, every additional day may imply a longer life expectancy.

The longer a technology lives, the longer it can be expected to live.

Things that have been around for a long time are not “aging” like persons, but “aging” in reverse. Every year that passes without extinction doubles the additional life expectancy.

Gott made a list of Broadway shows on a given day, May 17, 1993, and predicted that the longest-running ones would last longest, and vice versa. He was proven right with 95 percent accuracy.

The mistake is to believe that one would be acting “young” by adopting a “young” technology.

The illusion of the contribution of the new generations over the old - statistically, the “young” do almost nothing.

Much progress comes from the young because of their relative freedom from the system and courage to take action that older people lose as they become trapped in life. But it is precisely the young who propose ideas that are fragile, not because they are young, but because most unseasoned ideas are fragile. And, of course, someone who sells “futuristic” ideas will not make a lot of money selling the value of the past! New technology is easier to hype up.

Read the classics. The future is in the past.

We rely more on water than on cell phones but because water does not change and cell phones do, we are prone to thinking that cell phones play a larger role than they do.

We ignore that these implementations don’t usually stick. Most “innovations” are failures.

When Lebanese run into Syrians, they focus on the tiny variations in their respective Levantine dialects, but when Lebanese run into Italians, they focus on similarities.

A city should be devoted to pedestrians.

More than a third of the residents in London are foreign-born.

Books that are one year old are usually not worth reading, no matter the hype and how “earth-shattering” they may seem to be.

Time can act as a cleanser of noise by confining to its dustbins all these overhyped works.

Seemingly uninteresting results that go unnoticed, can, years later turn out to be breakthroughs.

Companies that get hyped up for their potential and called “best” on the cover of magazines or in books such as Good to Great are about to underperform and one can derive an abnormal profit by shorting their stock).

Get the proceedings of a random conference that took place five years ago. Odds are it will feel no different from a five-year-old newspaper.

Attending breakthrough conferences might be a waste of time.

Amateurs in any discipline are the best.

Career professionals are to knowledge what prostitutes are to love.

What to read: As little as feasible from the last twenty years, except history books that are not about the last fifty years.

Corporations that are large today should be gone, as they have always been weakened by what they think is their strength: size, which is the enemy of corporations as it causes disproportionate fragility.

Opinions pop up, as if reality cared about opinions and narratives. There are secrets to our world that only practice can reveal.

This secret property is, of course, revealed through time, and, thankfully, only through time.

The doctor insisted that I should “ice” my nose. The swelling was my own body’s response to the injury. It seemed to me that it was an insult to Mother Nature to override her programmed reactions unless we had a good reason to do so, backed by proper empirical testing to show that we humans can do better; the burden of evidence falls on us humans. There is no compelling empirical evidence in favor of the reduction of swelling.

It was pure sucker-rationalism in the mind of doctors, following what made sense to boundedly intelligent humans, coupled with interventionism, this need to do something.

Empiricism: the onus is on the doctors to show us why reducing fever is good, why eating breakfast before engaging in activity is healthy (there is no evidence).

The hidden costs of health care are largely in the denial of antifragility.

Diseases of civilization result from the attempt by humans to make life comfortable for ourselves against our own interest, since the comfortable is what fragilizes.

In the very ill condition, the benefits are large relative to iatrogenics; in the borderline one, they are small. This means that we need to focus on high-symptom conditions and ignore, I mean really ignore, other situations in which the patient is not very ill.

Mother Nature had to have tinkered through selection in inverse proportion to the rarity of the condition. Of the hundred and twenty thousand drugs available today, I can hardly find a via positiva one that makes a healthy person unconditionally “better”

When you think you have found a free lunch, say, steroids or trans fat, something that helps the healthy without visible downside, it is most likely that there is a concealed trap somewhere.

Why we have not been able to find drugs that make us feel unconditionally better when we are well (or unconditionally stronger, etc.): nature would have been likely to find this magic pill by itself.

What Mother Nature does is rigorous until proven otherwise; what humans and science do is flawed until proven otherwise.

Overriding nature requires some very convincing justification on our part.

Lifting weights increases your muscle mass . In the past they used to say that weight lifting caused the “micro-tearing of muscles,” with subsequent healing and increase in size. Today some people discuss hormonal signaling or genetic mechanisms, tomorrow they will discuss something else. But the effect has held forever and will continue to do so.

Theories come and go; experience stays.

Add neurosomething to a field, and suddenly it rises in respectability and becomes more convincing as people now have the illusion of a strong causal link.

An attribution problem arises when the person imputes his positive results to his own skills and his failures to luck. Applied to stockbrokers, doctors, and managers of companies.

No doctor derives pleasure from the health of his friends, no soldier from the peace of his city.

All these biases lead to action, almost never inaction.

To be sophisticated you need to accept that you are not so.

Ancestral men tended to die of trauma.

The gains in life expectancy are more societal than from the result of scientific advance.

We can cure many cases of diabetes by putting people on a very strict starvation-style diet, shocking their system.

Drink no liquid that is not at least a thousand years old - so its fitness has been tested.

Money has its own iatrogenics. Separating some people from their fortune would simplify their lives and bring great benefits in the form of healthy stressors.

If you take risks and face your fate with dignity, there is nothing you can do that makes you small; if you don’t take risks, there is nothing you can do that makes you grand, nothing. And when you take risks, insults by half-men (small men, those who don’t risk anything) are similar to barks by nonhuman animals: you can’t feel insulted by a dog.

Hammurabi’s code: Reestablish a symmetry of fragility: If a builder builds a house and the house collapses and causes the death of the owner of the house - the builder shall be put to death. If it causes the death of the son of the owner of the house, a son of that builder shall be put to death.

The builder knows more, a lot more, than any safety inspector, particularly about what lies hidden in the foundations - making it the best risk management rule ever, as the foundation, with delayed collapse, is the best place to hide risk.

Save lives by providing up-front disincentive in case of harm to others during the fulfillment of one’s profession.

The English had the families of the engineers spend time with them under the bridge after it was built.

Every opinion maker needs to have “skin in the game” in the event of harm caused by reliance on his information or opinion. No opinion without risk.

It's profoundly unethical to talk without doing, without exposure to harm, without having one’s skin in the game, without having something at risk. You express your opinion; it can hurt others (who rely on it), yet you incur no liability. Is this fair?

Never ask anyone for their opinion, forecast, or recommendation. Just ask them what they have - or don’t have - in their portfolio.

The best poet - in any language?- Odds are Almutanabbi.

Corporate managers have incentives without disincentives - managers of businesses that are not owner-operated.

Company executives are no entrepreneurs - just actors, slick actors (business schools are more like acting schools).

Someone intelligent - or free - would likely implode under such a regimen.

A corporation does not feel pity. A corporation does not have a sense of honor.

A corporation does not have generosity. Only self-serving actions are acceptable. Just imagine what would happen to a corporation that decided to unilaterally cancel its receivables - just to be nice. Yet societies function thanks to random acts of generosity between people, even sometimes strangers. All of these defects are the result of the absence of skin in the game.

Only a sense of honor can lead to commerce. Any commerce.

One can rapidly become enslaved to a profession, to the point of having one’s opinions on any subject become self-serving, hence unreliable for the collective.

For the English, humanity started at the rank of idle freeman, unpreoccupied with work. It never meant not working; it just meant not deriving your personal and emotional identity from your work, and viewing work as something optional, more like a hobby. In a way your profession does not identify you so much as other attributes.

For Fat Tony, humanity started at the level of “self-ownership.” Being the owner of your opinion. And it has nothing to do with wealth, birth, intelligence, looks, shoe size, rather with personal courage.

Definition of a free person: someone who cannot be squeezed into doing something he would otherwise never do.

Anyone who goes into public service should not be allowed to subsequently earn more from any commercial activity than the income of the highest paid civil servant. It is like a voluntary cap (it would prevent people from using public office as a credential-building temporary accommodation, then going to Wall Street to earn several million dollars).

One should give more weight to witnesses and opinions when they present the opposite of a conflict of interest. A pharmacist or an executive of Big Pharma who advocates starvation and via negativa methods to cure diabetes would be more credible than another one who favors the ingestion of drugs.

Education, in the sense of the formation of character, personality, and acquisition of true knowledge, likes disorder; label-driven education and educators abhor disorder.

Innovation is precisely something that gains from uncertainty: and some people sit around waiting for uncertainty and using it as raw material.