Hitchens's razor

Hitchens's razor is an epistemological razor that serves as a general rule for rejecting certain knowledge claims. It states:

The razor is credited to author and journalist Christopher Hitchens, although its provenance can be traced to the Latin Quod gratis asseritur, gratis negatur ("What is asserted gratuitously is denied gratuitously"). It implies that the burden of proof regarding the truthfulness of a claim lies with the one who makes the claim; if this burden is not met, then the claim is unfounded, and its opponents need not argue further in order to dismiss it. Hitchens used this phrase specifically in the context of refuting religious belief.

The dictum appears in Hitchens's 2007 book God Is Not Great: How Religion Poisons Everything. The term "Hitchens's razor" itself first appeared (as "Hitchens' razor") in an online forum in October 2007, and was used by atheist blogger Rixaeton in December 2010, and popularised by, among others, evolutionary biologist and atheist activist Jerry Coyne after Hitchens died in December 2011.

Some pages earlier in God Is Not Great, Hitchens also invoked Occam's razor. William Ockham devised a principle of economy, popularly known as Ockham's razor, which relied for its effect on disposing of unnecessary assumptions and accepting the first sufficient explanation or cause: "Do not multiply entities beyond necessity." This principle extends itself: "Everything which is explained through positing something different from the act of understanding can be explained without positing such a distinct thing."

In 2007, Michael Kinsley observed in The New York Times that Hitchens was rather fond of applying Occam's razor to religious claims, and according to The Wall Street Journal's Jillian Melchior in 2017, the phrase "What can be asserted without evidence can be dismissed without evidence" was "Christopher Hitchens's variation of Occam's razor". Hitchens's razor has been presented alongside the Sagan standard ("Extraordinary claims require extraordinary evidence") as an example of evidentialism within the New Atheism movement.

Academic philosopher Michael V. Antony argued that despite the use of Hitchens's razor to reject religious belief and to support atheism, applying the razor to atheism itself would seem to imply that atheism is epistemically unjustified. According to Antony, the New Atheists (to whom Hitchens also belonged) invoke a number of special arguments purporting to show that atheism can in fact be asserted without evidence.

Philosopher C. Stephen Evans outlined some common Christian theological responses to the argument made by Hitchens, Richard Dawkins, and the other New Atheists that if religious belief is not based on evidence, it is not reasonable, and can thus be dismissed without evidence. Characterising the New Atheists as evidentialists, Evans counted himself amongst the Reformed epistemologists together with Alvin Plantinga, who argued for a version of foundationalism, namely that "belief in God can be reasonable even if the believer has no arguments or propositional evidence on which the belief is based". The idea is that all beliefs are based on other beliefs, and some "foundational" or "basic beliefs" just need to be assumed to be true in order to start somewhere, and it is fine to pick God as one of those basic beliefs.

Additional criticism includes that, more often than not, the razor is invoked against a position that has at least prima facie evidence supporting it and hence should not be dismissed outright. While the nature of the evidence may be disputed, its existence cannot be ignored. Furthermore, Hitchens’s razor can prematurely shut down a potentially fruitful discussion if both parties choose to invoke it against each other. Based on these considerations, among others, theologian Randal Rauser sees Hitchens's razor as having a "deeply corrosive impact on reasoned discourse", lamenting that "those who invoke it are far less likely to consider the respective merits of evidence on both sides of an issue".