Nassim Nicholas Taleb born 1960 has three distinct careers (literary, scientific, and business) built around what he calls "epistemic limitations and constraints" (probability, uncertainty and the fragility of human knowledge): 1) bestselling literary essayist, 2) university professor in risk engineering (Distinguished Professor level), scholar, epistemologist, philosopher of science (probability and statistics), and 3) senior Wall Street trader, hedge fund manager, and practitioner of mathematical finance. Though a specialist in financial derivatives, Taleb has been critical of the finance industry and has been credited with making predictions regarding financial crises and making a fortune out of the 2008 crisis. He held senior trading and financial mathematics positions at a number of New York City's Wall Street firms before starting a second career as a scholar in the epistemology of chance, and as an activist and a promoter of what he calls a "Black Swan robust" society. He is also a promoter of aggressive "stochastic tinkering" as a means of scientific discovery. Taleb is a bestselling author with 2.7 million copies sold in 31 languages. His idiosyncratic writing style mixes narrative fiction (often semi-autobiographical) and short philosophical tales with historical and scientific commentary. Taleb's best-known book, The Black Swan, has been described by The Times as one of the 12 most influential books of the past 60 years. Among the people Taleb has influenced are the writer Malcolm Gladwell and the British Tory leader David Cameron who uses his black swan robustness idea as "intellectual ballast" for his program.