Nassim Nicholas Taleb

When conflicted between two choices, take neither.

The information that a person derived some profit in the past... by itself, is neither meaningful nor relevant. We need to know the size of the population from which he came. If the initial population is 10,000 managers, I would ignore the results.

[B]ecoming more rational, or not feeling the emotions of social slights, is not part of the human race... not with our current biology. There is no solace to be found from reasoning...

A mistake is not something to be determined after the fact, but in the light of the information until that point.

Many scientists... are... subject to such foolishness... One flagrant example is... global warming... These scientists initially ignored the fact that these [high temperature] spikes, although rare, had the effect of adding disproportionately to the cumulative melting of the ice caps. ...[A]n event, although rare, that brings large consequences cannot be ignored.

[E]conomists are evaluated on how intelligent they sound, not on a scientific measure of their knowledge of reality. (page 85)

There is no effective difference between guessing a variable that is not random, but for which information is partial or deficient (...), and a random one (...). In this sense, guessing (what I don't know, but what someone else may know) and predicting (what has not taken place yet) are the same thing.

Let us use 10,000 fictional investment managers... [O]nce a manager has a single bad year, he is thrown out of the sample. ...[T]oss a coin; heads and the manager will make $10,000 over the year, tails and he will lose $10,000. ...We have, in a fair game, 313 managers who made money five years in a row. ...[I]f we throw one of these ...into the real world we would get ...comments on his remarkable style, his incisive mind... His biographer will dwell on ...a great mind in the making. ...[S]hould he stop performing (...his odds ...have stayed at 50%) they would start ...finding fault with his dissipated lifestyle. They will find something he stopped doing, and attribute his failure... The truth ...he simply ran out of luck.

History is opaque. You see what comes out, not the script that produces events, [...] The generator of historical events is different from the events themselves, much as the minds of the gods cannot be read just by witnessing their deeds.

Categorizing is necessary for humans, but it becomes pathological when the category is seen as definitive, preventing people from considering the fuzziness of boundaries, let alone revising their categories.

Consider that the turkey's experience may have, rather than no value, a negative value. It learned from observation, as we are all advised to do (hey, after all, this is what is believed to be the scientific method). Its confidence increased as the number of friendly feedings grew, and it felt increasingly safe even though the slaughter was more and more imminent. Consider that the feeling of safety reached its maximum when the risk was at the highest!

I always remind myself that what one observes is at best a combination of variance and returns, not just returns.