Conza

In explicitly understanding knowledge as displayed in argumentation as a peculiar category of action, it becomes clear immediately why the perennial rationalist claim that the laws of logic—beginning here with the most fundamental ones, i.e., of propositional logic and of Junctors (“and,” “or,” “if-then,” “not”) and Quantors (“there is,” “all,” “some”)—are a priori true propositions about reality and not mere verbal stipulations regarding the transformation rules of arbitrarily chosen signs, as empiricist-formalists would have it, is indeed correct. They are as much laws of thinking as of reality; because they are laws that have their ultimate foundation in action and could not be undone by any actor. In each and every action, an actor identifies some specific situation and categorizes it one way rather than another in order to be able to make a choice. It is this which ultimately explains the structure of even the most elementary propositions (like “Socrates is a man”) consisting of a proper name or some identifying expression for the naming or identifying  of something, and a predicate to assert or deny some specific property of the named or identified object; and which explains the cornerstones of logic: the laws of identity and contradiction. And it is this universal feature of action and choosing which also explains our understanding of the categories “there is,” “all” and, by implication, “some,” as well as “and,” “or,” “if-then” and “not.”[58]

One can say, of course, that something can be “a” and “non-a” at the same time, or that “and” means this rather than something else. But one cannot undo the law of contradiction; and one cannot undo the real definition of “and.” For simply by virtue of acting with a physical body in physical space we invariably affirm the law of contradiction and invariably display our true constructive knowledge of the meaning of “and” and “or.”

~ Hans-Hermann Hoppe, Economic Science and the Austrian Method, On Praxeology and the Praxeological Foundation of Epistemology, III, pg 71.

• [58] On rationalist interpretations of logic see Blanshard, Reason and Analysis, chapters 6, 10; P. Lorenzen, Einfuhrung in die operative Logik und Mathematik (Frankfun/M.: Akademische Verlagsgesellschaft, 1970); K. Lorenz, Elemente der Sprachkritik (Frankfurt/M.: Suhrkamp, 1970); idem, “Diedialogische Rechtfertigung der effektiven Logik,” in: E Kambartel and J. Mittelstrass, eds., Zum normativen Fundament der Wissenschaft (Frankfurt/M.: Athenaum, 1973).

• On the propositional character of language and experience, in particular, see W. Kamlah and P. Lorenzen, Logische Propiideutik, chapter 1; P. Lorenzen, Normative Logic and Ethics, chapter 1. Lorenzen writes:

“I call a usage a convention if I know of another usage which I could accept instead.·… However, I do not know of another behavior which could replace the use of elementary sentences. If I did not accept proper names and predicators, I would not know how to speak at all… . Each proper name is a convention … but to use proper names at all is not a convention: it is a unique pattern of linguistic behavior. Therefore, I am going to call it ‘logical’. The same is true with predicators. Each predicator is a convention. This is shown by the existence of more than one natural language. But all languages use predicators” (ibid., p. 16). See also J. Mittelstrass, “Die Wiederkehr des Gleichen,” Ratio (1966).

• On the law of identity and contradiction, in particular, see B. Blanshard, Reason and Analysis, pp. 276ff, 423ff. On a critical evaluation of 3- or more-valued logics as either meaningless symbolic formalisms or as logically presupposing an understanding of the traditional two-valued logic see W Stegmiiller,  HauptstrOmungen der Gegenwartsphilosophie vol. 2 (Stuttgart: Kroner, 1975), pp. 182-91; B. Blanshard, Reason and Analysis, pp. 269-75. Regarding, for instance, the many-valued or open-textured logic, proposed by E Waismann, Blanshard notes: 

“We can only agree with Dr. Waismann-and with Hegel-that the black-and-white distinctions of formal logic are quite inadequate to living thought. But why should one say, as Dr. Waismann does, that in adopting a more differentiated logic one is adopting an alternative system which is incompatible with black-and-white logic? What he has actually done is to recognize a number of gradations within the older meaning of the word ‘not’. We do not doubt that such gradations are there, and indeed as many more as he cares to distinguish. But a refinement of the older logic is not an abandonment of it. It is still true that the colour I saw yesterday was either a determinate shade of yellow or not, even though the ‘not’ may cover a multitude of approximations, and even though I shall never know which was the shade I saw” (ibid., pp. 273-74).