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Philosophy Dictionary of Arguments
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Classes: In logic, a class is a collection of objects that share a common characteristic or property. Statements about classes can be expressed using logical symbols, such as "∈" for membership and "⊆" for subset. Identity of classes is provided by same elements (extension) - or identity of properties by the same predicates (intension). See also Sets, Set theory, Subsets, Element relation. - B. Classes in political theory refer to societal groups sharing economic interests, often defined by their relationship to production and resources. See also Society, Conflicts._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments.
Author
Concept
Summary/Quotes
Sources
H. Wessel on Classes - Dictionary of Arguments
I 360f
Class/Wessel: "What is a class?": Wrong question, without circularity it can only be introduced as a logical operator.
>Operators.
It is also circular as abstraction: requires individual domains.
>Circular reasoning.
Th concept of class and class logic superfluous, merely different representations of the concept of the propositional function and the classical quantifier logic.
>Propositional functions, >Quantifier logic, >Sets, >Set theory.
The class of Amazons exists as an empty class.
Def Class: if tA is a class term, then A is a class.
Problem: the left side is burdened by existence,the right side is not.
Solution: instead of identity only meaning equality of terms
(t €s P(s) <=> t €s Q(s)) =def As(P(s) ↔ Q(s)).
Thus a definition by abstraction becomes a mere facon de parler.
>Abstraction, >Class abstraction._____________Explanation of symbols: Roman numerals
indicate the source, arabic numerals indicate
the page number. The corresponding books
are indicated on the right hand side.
((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments
The note [Concept/Author], [Author1]Vs[Author2] or [Author]Vs[term] resp. "problem:"/"solution:", "old:"/"new:" and "thesis:" is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.
Wessel I
H. Wessel
Logik Berlin 1999
Ed. Martin Schulz, access date 2024-04-28