Wikipedia:Today's featured article/March 12, 2024

The Sagan standard is the aphorism that "extraordinary claims require extraordinary evidence". It is named for Carl Sagan (pictured), who used the phrase in his 1979 book Broca's Brain. The standard has been described as fundamental to the scientific method and is regarded as encapsulating the basic principles of scientific skepticism. The Sagan standard is similar to Occam's razor in that both prefer simpler explanations to more complex ones. The Sagan standard is often invoked to challenge data and scientific findings, or to criticize pseudoscientific claims. Similar statements were previously made by figures such as Thomas Jefferson in 1808, Pierre-Simon Laplace in 1814, and Théodore Flournoy in 1899. The formulation "Extraordinary claims require extraordinary proof" was used a year prior to Sagan, by scientific skeptic Marcello Truzzi. It has also been argued that philosopher David Hume first fully characterized the principles of the Sagan standard in his 1748 essay "Of Miracles".