Free thought holds that individuals should not accept ideas
proposed as truth without recourse to knowledge and reason. Thus, freethinkers
strive to build their opinions on the basis of facts, scientific inquiry, and
logical principles, independent of any logical fallacies or the intellectually
limiting effects of authority, confirmation bias, cognitive bias, conventional
wisdom, popular culture, prejudice, sectarianism, tradition, urban legend, and
all other dogmas. Regarding religion, freethinkers hold that there is insufficient
evidence to support the existence of supernatural phenomena.
A line from "Clifford's Credo" by the 19th Century
British mathematician and philosopher William Kingdon Clifford perhaps best
describes the premise of free thought: "It is wrong always, everywhere,
and for anyone, to believe anything upon insufficient evidence."