Verisimilitude
{{Short description|Resemblance to reality}}
{{for multi|verisimilitude in stories|Verisimilitude (fiction)|other uses|Verisimilitude (disambiguation)}}
{{essay|date=January 2012}}
In philosophy, verisimilitude (or truthlikeness) is the notion that some propositions are closer to being true than other propositions. The problem of verisimilitude is the problem of articulating what it takes for one false theory to be closer to the truth than another false theory.{{cite web|url = https://plato.stanford.edu/entries/truthlikeness/|title=Truthlikeness, Stanford Encyclopedia of Philosophy|access-date=2019-10-11}}
This problem was central to the philosophy of Karl Popper, largely because Popper was among the first to affirm that truth is the aim of scientific inquiry while acknowledging that most of the greatest scientific theories in the history of science are, strictly speaking, false. If this long string of purportedly false theories is to constitute progress with respect to the goal of truth, then it must be at least possible for one false theory to be closer to the truth than others.
Karl Popper
{{see also|Karl Popper#Truth}}
Popper's formal definition of verisimilitude was challenged since 1974 by Pavel Tichý,{{cite journal |author=Pavel Tichý |author-link=Pavel Tichý |title=On Popper's Definitions of Verisimilitude |journal=The British Journal for the Philosophy of Science |publisher=Oxford University Press |date=June 1974 |volume=25 |issue=2 |pages=155–160 |jstor=686819 |doi=10.1093/bjps/25.2.155}}{{cite journal |author=Pavel Tichý |title=Verisimilitude Redefined |journal=The British Journal for the Philosophy of Science |date=March 1976 |volume=27 |issue=1 |pages=25–42 |jstor=686376 |doi=10.1093/bjps/27.1.25}} John Henry Harris,{{cite journal |author=John H. Harris |author-link=John Henry Harris (philosopher) |title=Popper's Definitions of 'Verisimilitude' |journal=The British Journal for the Philosophy of Science |date=June 1974 |volume=25 |issue=2 |pages=160–166 |jstor=686820 |doi=10.1093/bjps/25.2.160}} and David Miller,{{cite journal |author=David Miller |author-link=David Miller (philosopher) |title=Popper's Qualitative Theory of Verisimilitude |journal=The British Journal for the Philosophy of Science |date=June 1974 |volume=25 |issue=2 |pages=166–177 |jstor=686821 |doi=10.1093/bjps/25.2.166}} who argued that Popper's definition has an unintended consequence: that no false theory can be closer to the truth than another. Popper himself stated: "I accepted the criticism of my definition within minutes of its presentation, wondering why I had not seen the mistake before."{{cite book |author=Karl Popper |author-link=Karl Popper |editor=W. W. Bartley III |editor-link=W. W. Bartley III |title=Realism and the Aim of Science. From the Postscript to the Logic of Scientific Discovery |url=https://books.google.com/books?id=tlowU8nS2ygC |year=2013 |orig-date=1983 |publisher=Routledge |location=Abingdon-on-Thames |isbn=978-1-1358-5895-7 |page=[https://books.google.com/books?id=tlowU8nS2ygC&dq=%22I+accepted+the+criticism+of+my+definition+within+minutes+of+its+presentation,+wondering+why+I+had+not+seen+the+mistake+before%22&pg=PR36 xxxvi]}} This result gave rise to a search for an account of verisimilitude that did not deem progress towards the truth an impossibility.
Post-Popperian theories
Theories proposed by David Miller and by Theo Kuipers build on Popper's approach, guided by the notion that truthlikeness is a function of a truth factor and a content factor. Others (e.g. those advanced by {{ill|Gerhard Schurz|de}} in collaboration with {{ill|Paul Weingartner|de}}, by Mortensen, and by Ken Gemes) are also inspired by Popper's approach but locate what they believe to be the error of Popper's proposal in his overly generous notion of content, or consequence, proposing instead that the consequences that contribute to closeness to truth must be, in a technical sense, "relevant". A different approach (already proposed by Tichý and {{ill|Risto Hilpinen|fi}} and developed especially by Ilkka Niiniluoto and Graham Oddie) takes the "likeness" in truthlikeness literally, holding that a proposition's likeness to the truth is a function of the overall likeness to the actual world of the possible worlds in which the proposition would be true. An attempt to use the notion of point-free metric space is proposed by Giangiacomo Gerla.{{cite book|first=Graham |last=Oddie|title= Truthlikeness|work=Stanford Encyclopedia of Philosophy|year=2016|publisher=Metaphysics Research Lab, Stanford University|url= http://plato.stanford.edu/entries/truthlikeness/}} There is currently a debate about whether or to what extent these different approaches to the concept are compatible.{{cite journal | author = Zwart S. D., Franssen M. | year = 2007 | title = An impossibility theorem for verisimilitude | url = https://repository.tudelft.nl/islandora/object/uuid%3A6aeb2104-e4ce-452c-a141-a47c6d93c9c3/datastream/OBJ/download| journal = Synthese | volume = 158 | issue = 1| pages = 75–92 | doi=10.1007/s11229-006-9051-y| s2cid = 28812992 }}{{cite journal | author = Oddie Graham | year = 2013 | title = The content, consequence and likeness approaches to verisimilitude: compatibility, trivialization, and underdetermination | journal = Synthese | volume = 190 | issue = 9| pages = 1647–1687 | doi=10.1007/s11229-011-9930-8| s2cid = 15527839 }}{{cite journal | author = Gerla G | year = 2007 | title = Point free geometry and verisimilitude of theories | journal = Journal of Philosophical Logic | volume = 36 | issue = 6| pages = 707–733 | doi=10.1007/s10992-007-9059-x| s2cid = 29922810 }}
See also
{{Wiktionary}}
References
{{Reflist|30em}}
{{Karl Popper}}
Category:Concepts in epistemology
Category:Concepts in the philosophy of science