|Logic: logic is the doctrine of the admissibility or inadmissibility of relations between statements and thus the validity of the compositions of these statements. In particular, the question is whether conclusions can be obtained from certain presuppositions such as premises or antecedents. Logical formulas are not interpreted at first. Only the interpretation, i. e. the insertion of values, e.g. objects instead of the free variables, makes the question of their truth meaningful._____________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. |
Grammar/Logic: subject/predicate: always a thought, without a truth value, no extension.
Tugendhat II 54
Hegel: logic is composed of concepts- FregeVsHegel: it is not composed of concepts, but of sentences! Important: not objects can be negated, but only sentences.
Thiel I 335
Logic/Frege/Thiel: Frege's concept of logic, on which he wanted to trace back the entire non-geometric mathematics, was a further one than that of today.
For Frege, the formation of sets is a logical process, so that the transition from the statement that exactly the same objects fall under two terms A and B to the statement of equality of the conceptual scopes of A and B is a law of logic for Frege.
Today's view: conceptual scopes are nothing more than sets, therefore the law does not belong to logic, but to set theory.
In Traditional Logic, the doctrine of conceptual extents was part of logic. Today it is part of set theory, while the doctrine of "conceptual content" remains in logic. That is rather weird._____________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.
Die Grundlagen der Arithmetik Stuttgart 1987
Funktion, Begriff, Bedeutung Göttingen 1994
Logische Untersuchungen Göttingen 1993
Vorlesungen zur Einführung in die Sprachanalytische Philosophie Frankfurt 1976
Philosophische Aufsätze Frankfurt 1992
Philosophie und Mathematik Darmstadt 1995