Logic
Logic is a subfield of philosophy, of mathematics and of computer science which investigates the structure of statements and arguments, both in natural language and in artificial languages. It is mainly seen as a prescriptive field formulating principles on how we ought to think (in opposition to psychology which is the empirical study about how human actually think).
As documented by Wikipedia (2006) there is some controversies about the nature of logic.
In Library and Information Science (LIS) is logical problems known from, for example, Boolean search. Olson (2007) states that logic has been criticized from a feminist point of view and quotes some of this criticism. She also considers the role of logic in knowledge organization:
"To
organize information, librarians create structures. These structures grow from a
logic that goes back at least as far as Aristotle. It is the basis of
classification as we practice it, and thesauri and subject headings have
developed from it. Feminist critiques of logic suggest that logic is gendered in
nature. This article will explore how these critiques play out in contemporary
standards for the organization of information. Our widely used classification
schemes embody principles such as hierarchical force that conform to
traditional/Aristotelian logic. Our subject heading strings follow a linear path
of subdivision. Our thesauri break down subjects into discrete concepts. In
thesauri and subject heading lists we privilege hierarchical relationships,
reflected in the syndetic structure of broader and narrower terms, over all
other relationships. Are our classificatory and syndetic structures gendered?
Are there other options? Carol Gilligan's In a Different Voice (1982), Women's
Ways of Knowing (Belenky, Clinchy, Goldberger, & Tarule, 1986), and more recent
related research suggest a different type of structure for women's knowledge
grounded in "connected knowing." This article explores current and potential
elements of connected knowing in subject access with a focus on the
relationships, both paradigmatic and syntagmatic, between concepts. "
Literature:
Gabby, D. M. & Woods, John (Eds.). (2004-). Handbook of the History of Logic Vol. 1- . Amsterdam: North Holland.
1: Greek, Indian & Arabian Logic. 2004.
2: Mediaeval and Renaissance Logic. 2008.
3: The Rise of Modern Logic: from Leibniz to Frege. 2004.
4: British Logic in the Nineteenth Century. 2008.
5:
6:
7: Logic and the Modalities in the Twentieth Century. 2006.
8: The Many Valued and Nonmonotonic Turn in Logic. 2007.
Folke Larsen, S. (1980). Egocentrisk tale, begrebsudvikling og semantisk udvikling. Nordisk Psykologi, 32(1), 55-73.
Olson, Hope A. (2007). How we
construct subjects: a feminist analysis. Library Trends,
Rosch, E. H. (1973). On the internal structure of perceptual and semantic categories.
IN: T. E. Moore (ed): Cognitive development and the acquisition of language. New York:
Academic Press.
Wikipedia. The free encyclopedia. (2006). Logic. http://en.wikipedia.org/wiki/Logic
Wittgenstein, L. (1953). Philosophical investigations. Oxford: Blackwell.
See also: Boolean search;
Fuzzy logic;
Information science, related
fields
Birger Hjørland
Last edited: 24-02-2008
to be edited:
I følge den klassiske, aristoteliske logik skelnes imellem et begrebs ekstension
og intension. Begrebets ekstension, omfang er den samling af faktiske
genstande eller fænomener, som begrebet omfatter. Begrebets intension, indhold
er den samling egenskaber, som de genstande, der er omfattet af begrebet har til
fælles, d.v.s. begrebets definerende træk. Den klassiske logik medfører en
*klassifikation, hvor alle elementer i en klasse har et givent sæt af
egenskaber, som ikke svarer til definitionen af andre klasser.
Denne klassiske logik fungerer indenfor visse snævre rammer, og botanikken kan
nævnes som eksempel. L. Wittgenstein (1953) har med sit begreb
"familieligheder" (især videreudviklet af Eleanor Rosch, 1973) i høj grad
udfordret den klassiske logik. Begrebet "grøntsag" er således ikke defineret ved
et sæt egenskaber, der er fælles for alle grøntsager og ikke findes hos
ikke-grøntsager. Der er flydende overgange ved hvad man opfatter som grøntsager,
og nogle grøntsager, f.eks. gulerødder er prototypiske grøntsager. Jo højere
grad af lighed med en prototype, desto større tendens til at opfatte den som
medlem af klassen grøntsager.
Denne erkendelse har konsekvenser for *klassifikation også i
*informationsvidenskaben. Den moderne tendens til at tale om *Klynger,
"Fuzzy-logik" m.v. hænger sammen med begrænsningerne i den klassiske logik.