Walther Brüning

Walther Brüning (born April 12, 1927 in Darmstadt ) is a German philosopher.

Life

He studied philosophy, natural and cultural sciences at the universities of Freiburg im Breisgau , Frankfurt am Main and Mainz. After graduating as Dr. phil. in Mainz on February 16, 1952 and habilitation there in 1959, he taught there from 1968 to 1992 as a professor of philosophy.

Strict logic

Walther Brüning developed a theory of "Strict General Logic" in his book Basics of Strict Logic , published in 1996 . According to Brüning, facts and contextual connections should only presuppose the principle of limitation (philosophy) and identity , as well as affirmation and negation . This should enable her to avoid transgressions, ie violations of these principles, which distinguishes her from symbolic / mathematical / modern logic .

The book begins with the strict syllogistics (he describes the traditional syllogistics in the context of his theory and expands it as a sub-area or special case of the strict logic). Only then does he describe a systematic structure of his first general logic and later certain aspects of special logics , depending on the traditional treatment. Then he introduces individuals and thus establishes his applied logic . Finally, he contrasts his strict logic with transgressive forms .

First is always a fact . It does not matter whether a statement , a class or a predicate is meant. The main thing is that this fact is logically clear, i.e. subject to the principle of identity and limitation. There is exactly one difference that defines the sub-area of ​​the issue from its differentiated part in the basic area. The first level is called single-digit or henadic. The rest of the basic area is the complementary matter. The application of value provide an associated validity value formula is thus two. The validity values can now be true or false . So there are 4 possible combinations (in mathematical logic no complementary facts are distinguished and there are only 2 possibilities.). The second level deals with two issues, etc. For every n issues there are validity value points per level and validity value combinations per level. The possible combinations (facts and combinations of facts ) of the validity values ​​are synthetic . All the derivations that result from this are analytical . All factual connections are in contradiction to one another, but above all by admitting indefinite values ​​(i.e. either true or false), many deductions can be made. Derivations can be made within a level or between levels using appropriate rules. The few different rules of derivation also follow the logical principles. Unless formulas of different stages or prolonged formulas lower level are involved, resulting in the formulas equating that remain the same in the extension of a (so to speak "uninvolved") facts. There are many possibilities of drawing conclusions from very few facts. They are studied in more detail in the book. ${\displaystyle 2^{n}}$ ${\displaystyle 2^{2^{n}}}$

Individual aspects are then dealt with in more detail in the special logic . In predicate logic, conditional inferences are dealt with, such as the modus ponens , the disjunctive inference and the like. In the class logic z. B. Selection operators (e.g. intersection and union ) are explained and placed in certain relationships to classes. In propositional logic, e.g. B. Treated derivations like and conditional conclusions. In addition, the relationship and modal logic are discussed. ${\displaystyle p\sqcap q\to p}$

In the chapter on transgressions, i.e. violations of the two principles, he explains, for example, why strict logic does not apply. The indirect proof is also not universal. ${\displaystyle p\to (p\lor q)}$

In the various places, the reflexivity (inadmissible, only identity possible), the subset of the same set (also), the conditions of existence of the traditional syllogistics (A-requirements in the validity formulas of the categorical judgments), antinomies and undecidivities (are avoidable), as well as the ambiguity of negation (negation / negation of the basic area of ​​a fact or affirmation / affirmation of a complementary fact).

Fonts (selection)

• The concept of law in the positivism of the Viennese school . Meisenheim am Glan 1954, OCLC 800493679 .
• Philosophical anthropology. Historical conditions and current status . Stuttgart 1960, OCLC 912271070 .
• Philosophy of History of the Present . Stuttgart 1961, OCLC 70348528 .
• Basics of strict logic . Würzburg 1996, ISBN 3-8260-1204-6 .

Individual evidence

1. ↑ Basics of Strict Logic. Wuerzburg 1996.