Editing Moore's paradox (section)

{{short description|Philosophical paradox concerning seemingly-absurd assertions}}
{{distinguish|Langford–Moore paradox|Moore's law}}
'''Moore's paradox''' concerns the apparent absurdity involved in asserting a first-person present-tense sentence such as "It is raining, but I do not believe that it is raining" or "It is raining, but I believe that it is not raining." The first author to note this apparent absurdity was [[G. E. Moore|George E. Moore]].<ref name="ReferenceA">{{Cite book |first=G. E. |last=Moore |chapter=Moore's Paradox |editor-first=Thomas |editor-last=Baldwin |title=G. E. Moore: Selected Writings |location=London |publisher=Routledge |year=1993 |pages=207–212 |isbn=978-0-415-09853-3 }}</ref> These 'Moorean' sentences, as they have become known, are paradoxical in that while they appear absurd, they nevertheless
# Can be true;
# Are (logically) consistent; and
# Are not (obviously) [[contradiction]]s.
The term 'Moore's paradox' is attributed to [[Ludwig Wittgenstein]],<ref>{{Cite book |first=Ludwig |last=Wittgenstein |title=Philosophical Investigations |publisher=Blackwell Publishers |year=1953 |others=Section II.x |page=190 }}</ref> who considered the paradox Moore's most important contribution to philosophy.<ref>{{Cite book |first=Ludwig |last=Wittgenstein |title=Letters to Russell, Keynes and Moore |editor-first=G. H. |editor-last=von Wright |location=Oxford |publisher=Blackwell Publishers |year=1974 }}</ref> Wittgenstein wrote about the paradox extensively in his later writings,{{efn|See especially ''[[On Certainty]]'' and ''[[Philosophical Investigations]]''.}} which brought Moore's paradox the attention it would not have otherwise received.<ref>{{Cite book |first=Ludwig |last=Wittgenstein |title=[[Remarks on the Philosophy of Psychology]], Volume I |editor1-first=G. E. M. |editor1-last=Anscombe |editor2-first=G. H. |editor2-last=von Wright |others=Translated by G. E. M. Anscombe |location=Oxford |publisher=Blackwell Publishers |year=1980 |isbn=978-0-631-12541-9 }}</ref> 

Moore's paradox has been associated with many other well-known [[paradox#Logical paradox|logical paradoxes]], including, though not limited to, the [[liar paradox]], the [[knower paradox]], the [[unexpected hanging paradox]], and the [[preface paradox]].<ref name="Sorensen">{{Cite book |first=Roy A. |last=Sorensen |year=1988 |title=Blindspots |location=New York |publisher=Oxford University Press |isbn=978-0-19-824981-8 }}</ref>

There is currently not any generally accepted explanation of Moore's paradox in the philosophical literature. However, while Moore's paradox remains a philosophical curiosity, Moorean-type sentences are used by [[logician]]s, [[computer scientist]]s, and those working with [[artificial intelligence]] as examples of cases in which a knowledge, belief, or information system is not modified in response to new data.<ref>{{cite journal | last1=Hendricks | first1=Vincent F. | last2=Symons | first2=John | title=Where's the Bridge? Epistemology and Epistemic Logic | journal=Philosophical Studies | volume=128 | issue=1 | year=2006 | issn=0031-8116 | doi=10.1007/s11098-005-4060-0 | pages=137–167| citeseerx=10.1.1.330.3026 | s2cid=11014804 }}</ref>