Taleb’s black swan theory states that dramatic unexpected events matter more to history than regular happenings. He advocates a “black swan robust” society that can benefit from difficult-to-predict events, and an approach to stock market investment that exploits risk, with “black swan” hedge funds thriving on sharp market downturns.
Our bird plays a starring role in all this owing to a belief in Europe, dating back 2000 years to Roman poet Juvenal, that swans are invariably white. Like purple cows and flying pigs, the black swan was a symbol of what was impossible. In medieval Europe, unicorns had more credibility. Dutch navigator Willem de Vlamingh, by finding black swans in Western Australia in 1697, showed how risky it is to declare something impossible.
The philosopher John Stuart Mill, writing in A System of Logic in 1843, used the statement “all swans are white” to show how large numbers of consistent observations can encourage a wrong induction. Karl Popper used the “black swan fallacy” to show that scientific ideas can never be proven true, only falsified. Bertrand Russell was yet another leading philosopher to invoke black swans in this way, in his 1912 book The Problems of Philosophy.