Abstract

Summary Influenced by the account of K. Popper and, moreover, of C. G. Hempel and P. Oppenheim, it is generally assumed, that a prediction can be logically deduced from hypotheses, i. e. lawlike propositions, and initial conditions. It is not clear, in which respect a prediction can correctly be supposed to be a proposition which is either true or false. From a logical point of view, serious difficulties arise in assuming that the deductive-nomological model consists of a valid argument. Further objections to this account are developed with regard to lawlike propositions. Since a lawlike proposition is — by definition — not true or definitely true, but only supposed to be true, it cannot function as a true premise among other true premises for the purpose of deduction. Special difficulties arise with regard to predictions: A predictive argument does not give any reason for the truth of the predictionK, but only — if at all — for the prediction of the truth ofK. In the latter case, the conclusion K clearly does not consist of a proposition (which could be either true or false) but rather of a predicting proposition