Philosophical razor

{{Short description|Principle that allows one to eliminate unlikely explanations}}

{{Use DMY dates|date=December 2023}}

In philosophy, a razor is a principle or rule of thumb that allows one to eliminate (shave off) unlikely explanations for a phenomenon, or avoid unnecessary actions.{{multiref2 | {{cite web |last=Garg |first1=Anu |date=17 May 2010 |title=Occam's razor |url=http://wordsmith.org/words/ockhams_razor.html |work=A.Word.A.Day |access-date=25 February 2014 |archive-url= https://web.archive.org/web/20140309141027/http://wordsmith.org/words/ockhams_razor.html |archive-date=9 March 2014 |url-status=live}} | {{Cite book |last=Downie |first=R. S. |date=November 1989 |chapter=Moral Philosophy |editor-last1=Eatwell |editor-first1=John |editor-last2=Milgate |editor-first2=Murray |editor-last3=Newman |editor-first3=Peter |title=The Invisible Hand |chapter-url= https://books.google.com/books?id=uqqwCwAAQBAJ&q=philosophical+razor&pg=PA213 |pages=213–222 |publisher=Palgrave MacMillan |isbn=9781349203130}} | {{cite book |editor-last=McLean |editor-first=Sheila A. M. |date=2013 |title=First Do No Harm: Law, Ethics and Healthcare |url= https://books.google.com/books?id=am2iVvW6pwEC&q=philosophical+razor&pg=PA18 |publisher=Ashgate |isbn=9781409496199}} }}

• Alder's razor (also known as Newton's flaming laser sword): If something cannot be settled by experiment or observation, then it is not worthy of debate.{{cite journal |first=Mike |last=Alder |author-link=Mike Alder |date=2004 |title=Newton's Flaming Laser Sword |url=http://www.philosophynow.org/issues/46/Newtons_Flaming_Laser_Sword |journal=Philosophy Now |volume=46 |pages=29–33 |access-date=26 January 2018 |archive-url= https://web.archive.org/web/20171204031512/https://philosophynow.org/issues/46/Newtons_Flaming_Laser_Sword |archive-date=4 December 2017 |url-status=live}} Also available in PDF format: {{cite web |first=Mike |last=Alder |author-link=Mike Alder |date=2004 |title=Newton's Flaming Laser Sword |url= http://school.maths.uwa.edu.au/~mike/Newtons%20Flaming%20Laser%20Sword.pdf |publisher=University of Western Australia |work=Mike Alder's Home Page |archive-url= https://web.archive.org/web/20111114041242/http://school.maths.uwa.edu.au/~mike/Newtons%20Flaming%20Laser%20Sword.pdf |archive-date=14 November 2011}}
• Grice's razor (also known as Guillaume's razor): As a principle of parsimony, conversational implicatures are to be preferred over semantic context for linguistic explanations.{{multiref2 | {{cite journal |last=Hazlett |first=A. |date=2007 |title=Grice's razor |journal=Metaphilosophy |volume=38 |issue=5 |page=669 |doi=10.1111/j.1467-9973.2007.00512.x}} | {{cite encyclopedia |chapter-url= https://plato.stanford.edu/entries/implicature/#GricTheo |title=Stanford Encyclopedia of Philosophy |chapter=Implicature, 6: Gricean Theory |url-status=live |archive-url= https://web.archive.org/web/20161211042732/https://plato.stanford.edu/entries/implicature/#GriThe |archive-date=11 December 2016 |access-date=27 December 2016}} }}
• Hanlon's razor: Never attribute to malice that which can be adequately explained by stupidity.{{cite web |url= http://catb.org/~esr/jargon/html/H/Hanlons-Razor.html |title=Hanlon's Razor |work=The Jargon File 4.4.7 |url-status=live |archive-url= https://web.archive.org/web/20110430025318/http://catb.org/~esr/jargon/html/H/Hanlons-Razor.html |archive-date=30 April 2011 |access-date=25 February 2014}}
• Hitchens' razor: That which can be asserted without evidence can be dismissed without evidence.{{cite book |url= https://www.oxfordreference.com/view/10.1093/acref/9780191826719.001.0001/q-oro-ed4-00004248 |title=Oxford Essential Quotations: Facts |date=2016 |publisher=Oxford University Press |isbn=9780191826719 |editor-last=Ratcliffe |editor-first=Susan |edition=4th |quote=What can be asserted without evidence can also be dismissed without evidence. |access-date=4 November 2020}}
• Hume's guillotine: What ought to be cannot be deduced from what is; prescriptive claims cannot be derived solely from descriptive claims, and must depend on other prescriptions. "If the cause, assigned for any effect, be not sufficient to produce it, we must either reject that cause, or add to it such qualities as will give it a just proportion to the effect."{{multiref2 | {{cite book |last=Miles |first=M. |title=Inroads: Paths in Ancient and Modern Western Philosophy |publisher=University of Toronto Press |date=2003 |isbn=978-0802037442 |page=[https://archive.org/details/inroadspathsinan0000mile/page/543 543] |via=Internet Archive}} | {{cite book |last1=Forrest |first1=P. |title=Reality and Humean Supervenience: Essays on the Philosophy of David Lewis |publisher=Rowman & Littlefield |date=2001 |isbn=978-0742512016 |editor1-last=Preyer |editor1-first=G. |editor2-last=Siebelt |editor2-first=F. |series=Studies in Epistemology and Cognitive Theory |page=93 |chapter=Counting the cost of modal realism |chapter-url= https://books.google.com/books?id=g0QCcG99otoC&pg=PA93 |via=Google Books}} }}
• Occam's razor: Explanations which require fewer unjustified assumptions are more likely to be correct; avoid unnecessary or improbable assumptions.
• Popper's falsifiability criterion: For a theory to be considered scientific, it must be falsifiable.{{cite book |last1=Popper |first1=Karl |author-link=Karl Popper |title=The Logic of Scientific Discovery |date=1972 |publisher=Hutchinson |isbn=9780091117207}}
• Sagan standard: Positive claims require positive evidence, extraordinary claims require extraordinary evidence.{{Cite book |last=Sagan |first=Carl |author-link=Carl Sagan |title=Broca's Brain: Reflections on the Romance of Science |date=2021 |publisher=Ballantine Books |isbn=978-0-345-33689-7 |location=New York}}