The Black Swan: The Impact of the Highly Improbable

Krasnova is a fictional character of Taleb’s creation. She is an unpublished writer who has married and divorced three philosopher husbands. Eventually her book, A Story of Recursion, gets picked up by a publisher and becomes a massive bestseller. The small publishing house enjoys financial success because of her book. A Story of Recursion is Krasnova's first Black Swan, as its success was utterly unpredictable. In the Epilogue, Krasnova experiences a second Black Swan, but this time her highly anticipated second book is a critical success but commercial failure. Logic would have led to the belief that the book would sell well. Its improbable underperformance is a Black Swan.

Umberto Eco (1932-2016) was an Italian writer and medievalist. He is perhaps best known for his novel The Name of the Rose, a murder mystery set in an Italian monastery during the 14th century. Eco's personal library is one of the foundational metaphorical images of Taleb’s book. Eco was more interested in the books he hadn't read. They were a reminder of all the things he didn't yet know or understand, while the books he had read represented mere drops in the bucket in his ongoing pursuit of knowledge. Taleb refers to Eco's collection of unread books as an antilibrary.

Giacomo Casanova was an Italian adventurer who lived during the 18th century. Casanova is notorious for being a legendary seducer, but he was also an aspiring intellectual. His twelve-volume work, History of My Life, contained lessons in the art of seduction and tales of his astounding good luck. Taleb brings up Casanova to prove a point about luck. Casanova's example illustrates that those who tell stories of triumph have been lucky enough to do so. For every Casanova, there are countless others who failed miserably in their pursuits.

Carl Friedrich Gauss (1777-1855) was a German mathematician whose theory on normal distribution eventually became known as the Gaussian bell curve. To this day, Gauss ranks among the most influential mathematicians to have ever lived. Yet, Taleb argues that the Gaussian bell curve is one of the primary logical fallacies when analyzing human history, particularly considering its tendency to obscure the effects of Black Swan events. Gauss himself did not intend for the bell curve to be used as a tool for historical analysis and interpretation. Taleb is scathing in his criticism of those who do, since, according to him, this provides the basis for a widespread delusion.

Benoit Mandelbrot (1924-2010) was a French-American mathematician. His work focused on understanding the often unpredictable or improbable elements of life by means of mathematics. Taleb cites Mandelbrot’s theory of fractal randomness, which according to Taleb accounts for Black Swans more than Gaussian bell curves do. Taleb coins the term "Mandelbrotian Gray Swan" to express his admiration for Mandelbrot's work. A Mandelbrotian Gray Swan is like a Black Swan. It is somewhat easier to explain and interpret, especially considering fractal randomness.