Now, crucially, time is equivalent to disorder, and resistance to the ravages of time, that is, what we gloriously call survival, is the ability to handle disorder.

That which is fragile has an asymmetric response to volatility and other stressors, that is, will experience more harm than benefit from it.

In probability, volatility and time are the same. The idea of fragility helped put some rigor around the notion that the only effective judge of things is time—by things we mean ideas, people, intellectual productions, car models, scientific theories, books, etc. You can’t fool Lindy: books of the type written by the current hotshot Op-Ed writer at The New York Times may get some hype at publication time, manufactured or spontaneous, but their five-year survival rate is generally less than that of pancreatic cancer.


Effectively Lindy answers the age-old meta-questions: Who will judge the expert? Who will guard the guard? (Quis custodiet impossible custodies?) Who will judge the judges? Well, survival will.

For time operates through skin in the game. Things that have survived are hinting to us ex post that they have some robustness—conditional on their being exposed to harm. For without skin in the game, via exposure to reality, the mechanism of fragility is disrupted: things may survive for no reason for a while, at some scale, then ultimately collapse, causing a lot of collateral harm.

A few more details. There are two ways things handle time. First there is aging and perishability: things die because they have a biological clock, what we call senescence. Second there is hazard, the rate of accidents. What we witness in physical life is the combination of the two: when you are old and fragile, you don’t handle accidents very well. These accidents don’t have to be external, like falling from a ladder or being attacked by a bear; they can also be internal, from random malfunctioning of your organs or circulation. On the other hand, animals that don’t really age, say turtles and crocodiles, seem to have a remaining life expectancy that stays constant for a long time. If a twenty-year-old crocodile has forty more years to live (owing to the perils of the habitat), a forty-year-old one will also have about forty years to live.

Let us use as shorthand “Lindy proof”, “is Lindy,” or “Lindy compatible” (one can substitute for another) to show something that seems to belong to the class of things that have proven to have the following property:

That which is “Lindy” is what ages in reverse, i.e., its life expectancy lengthens with time, conditional on survival.

Only the nonperishable can be Lindy. When it comes to ideas, books, technologies, procedures, institutions, and political systems under Lindy, there is no intrinsic aging and perishability. A physical copy of War and Peace can age (particularly when the publisher cuts corners to save twenty cents on paper for a fifty-dollar book); the book itself as an idea doesn’t.

Note that thanks to Lindy, no expert is the final expert anymore and we do not need meta-experts judging the expertise of experts one rank below them. We solve the “turtles all the way down” problem. (an expression that details the infinite regress problem, as follows. The logician Bertrand Russell was once told that the world sits on turtles. “And what do these turtles stand on?” he asked. “It’s turtles all the way down” was the answer.) Fragility is the expert, hence time and survival.


The idea of the Lindy effect is itself Lindy-proof. The pre-Socratic thinker Periander of Corinth wrote, more than twenty-five hundred years ago: Use laws that are old but food that is fresh.

Likewise, Alfonso X of Spain, nicknamed El Sabian, “the wise,” had as a maxim: Burn old logs. Drink old wine. Read old books. Keep old friends.

(142-144) Time, Volatility—Survival—Per…