The Vienna Circle: The Origins of Neo-Positivism by Victor Kraft

Author:Victor Kraft [Kraft, Victor]
Language: eng
Format: azw3
Publisher: Philosophical Library
Published: 2015-10-20T04:00:00+00:00

II. THE VERIFICATION-BASIS OF EMPIRICAL STATEMENTS

1. verifying Statements

Just as the Vienna Circle faced the clarification of the content of empirical concepts through their reduction to data of experience as a fundamental task of empiricism, so they took upon themselves the further task of clarifying the content and validity of empirical propositions through their reduction to elementary propositions. Here again Wittgenstein’s “Tractatus” served as the starting-point suggesting, at first, the general line of approach. Wittgenstein borrowed from Russell’s “Principia Mathematica” the fundamental division of propositions into compound and simple ones, “molecular” and “atomic” propositions. Atomic propositions are defined negatively as singular propositions which do not themselves contain propositions as components, where a singular proposition is any proposition which does not contain the concepts “all” or “some”. Molecular propositions are likewise singular, but they contain one or two or more atomic propositions. Such compound propositions have the form of conjunctions or disjunctions or implications or negations. Negative propositions also count as compound since they contain the proposition which is negated.

Wittgenstein, now, emphasized the new, important insight that the truth-value of compound propositions depends exclusively on the truth-values of the simple propositions which are their components; the former are “truth-functions” of the latter. Consequently, what alone matters is the truth-value of the simple, atomic propositions from which the truth-values of the compound propositions are derivable by pure logic.

The truth-conditions for propositions of the simplest form can be given directly: they are true if the object designated by the proper name has in fact the property or relation designated by the predicate. For the other forms of propositions, those containing component propositions, the truth-conditions are determined indirectly. Wittgenstein showed how the truth-value of conjunctions, disjunctions, implications and negations depends upon the truth-values of the component propositions, by virtue of the meanings of “and”, “or”, “if-then”, “not”, the “logical constants”. When two propositions are combined, there are many combinatorial possibilities of their truth-values, altogether 2n possibilities for propositions with n components. It can easily be seen that a conjunction of two propositions is true if and only if both component propositions are true; if, on the other hand, one or both component propositions are false, the conjunction itself is false. On the other hand, a disjunction involving the inclusive “or”, distinguished from the exclusive “either-or”, is false only if both component propositions are false. Similarly, an implication is true in three cases and false if the first component proposition, the antecedent, is true and the second, the consequent, is false. A negation is true if the negated proposition is false, and false if the negated proposition is true. But one could conversely define these forms of propositional connection in terms of the form of truth-dependence, by indicating what combinations of truth-values of the component propositions yield true propositions of the given form and what combinations yield false propositions of the given form. Thus the disjunction of propositions p and q is determined by the circumstance that it is true if both, or exactly one, proposition is true, and false only if both are false.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.