Razor razors were the most common form of shaving before the 20th century and remained common in many countries until the 1950s. Barbers were specially trained to give customers a thorough and quick shave, and a collection of straight razors ready for use was a common sight in most barbershops. Barbers still have them, but they use them less often. Straight razors eventually fell out of fashion. Their first challenger was manufactured by King C. Gillette: a double-edged safety razor with replaceable blades. Gillette's idea was the use of the "loss leader" concept, in which the razors were sold at a
Hitchens's razor by Hitchens published in 2007. Hitchens's razor is actually an English translation of the Latin proverb "" ("What is freely asserted is freely dismissed"), which was commonly used in the 19th century. It takes a stronger stance than the Sagan standard ("Extraordinary claims require extraordinary evidence"), instead applying to even non-extraordinary claims. Hitchens's razor Hitchens's razor is an epistemological razor asserting that the burden of proof regarding the truthfulness of a claim lies with the one who makes the claim, and if this burden is not met, the claim is unfounded, and its opponents need not argue further in order