Superforecasting: The Art and Science of Prediction

by Philip E. Tetlock

surprising. “Most people would identify science with certainty,” wrote the mathematician and statistician William Byers. “Certainty, they feel, is a state of affairs with no downside, so the most desirable situation would be one of absolute certainty. Scientific results and theories seem to promise such certainty.”14 In the popular mind, scientists generate facts and chisel them into granite tablets. This collection of facts is what we call “science.” As the work of accumulating facts proceeds, uncertainty is pushed back. The ultimate goal of science is uncertainty’s total eradication. But that is a very nineteenth-century view of science. One of twentieth-century science’s great accomplishments has been to show that uncertainty is an ineradicable element of reality. “Uncertainty is real,” Byers writes. “It is the dream of total certainty that is an illusion.”15 This is true both at the margin of scientific knowledge and at what currently appears to be its core. Scientific facts that look as solid as rock to one generation of scientists can be crushed to dust beneath the advances of the next.16 All scientific knowledge is tentative. Nothing is chiseled in granite.