The rejection of modern scientific judgements in favor of an irrational or superstitious beliefs. Practitioners of anti-science are hostile towards scientists, and may believe that science is a social behavior where truth is relative. Postmodernism, objectivism, creationism and alternative medicine are all examples of anti-science.

The term "anti-science" is attributed to Gerald Holton, a professor of physics and history at Harvard, who wrote "Science and Anti-Science" in 1993.