On May 29, 1919, a team of astronomers led by Sir Arthur Eddington photographed the star field behind a solar eclipse. Comparing the position of these stars at night, versus their position during the eclipse, they proved Einstein’s theory that starlight was deflected by the Sun’s gravity.
This experiment made a profound impression on Karl Popper, a young philosopher studying the scientific method. In order to be “scientific,” Popper wrote, a theory must make predictions that can be tested by experiment.
If Eddington’s team had not found the predicted result, Einstein’s theory would have been dead. As Popper wrote, “confirmations should count only if they are the result of risky predictions.” In his famous essay on falsifiability, he contrasts this with the work of Marx and Freud, also popular at the time.
In those theories, Popper found only confirmation bias: “you saw confirmed instances everywhere: the world was full of [post hoc] verifications of the theory.” A theory that is “irrefutable” is not scientific, he wrote. A scientific theory, like Einstein’s, must make definite predictions that could be disproved.
One hundred years later, Scott Adams would warn his readers against confirmation bias, directing them instead to test their ideas based on predictive power: “The best way to judge the accuracy of an idea is not by logic but by its predictive power. If an idea predicts the future accurately, it is a useful idea.”
Business leaders I have worked with pride themselves on “reality based” management. You can’t plan a strategy or launch a new investment based on an incorrect understanding of your market. Maintaining an accurate model of reality takes concerted effort. Read Popper’s full essay here
