This paper follows up the analysis of relativity theory begun by Margenau and Mould, by including electromagnetic theory which in their treatment was tacitly accepted. It is shown that the experiments on which Margenau and Mould rely to establish the special theory of relativity actually confirm the mutual consistency of the Maxwell-Lorentz electromagnetic theory and the special relativity theory, but throw no light on the validity of the two theories taken jointly. It is further shown that a modification of the rules of correspondence between the mathematical structure of the theories and immediate experience would bring the theories into agreement with an alternative relativity theory based on the Galilean instead of the Lorentz transformation. An experiment is suggested by which the need for such modification can be tested. A proof is then given that the rules of correspondence between the concepts of the special relativity theory (and therefore of current electromagnetic theory) and experience are not self-consistent, so that some modification of current ideas is essential. It is suggested that a generalisation of Maxwell's theory, in terms of Faraday's “ray vibrations” instead of Lorentz's static ether, might provide a satisfactory basis for a relativistic electromagnetic theory.

A phenomenalist philosophy which employs the Principle of Acquaintance (PA) plus the Principle that what exists are the referents of certain meaningful terms, defined by PA, cannot include either universals or particulars in its ontology, but is limited to instances of universals as constituting the range of ontological existents. Universals must be omitted since they are repeatable and, hence, never wholly presented or contained, whereas the objects of direct acquaintance are wholly and exhaustively presented. Furthermore, no entities beyond characters (qualities and relations) are given in direct acquaintance; hence, particulars, too, must be omitted for the phenomenalist who relies on PA.

The place of induction in the framing and test of scientific hypotheses is investigated. The meaning of ‘induction’ is first equated with generalization on the basis of case examination. Two kinds of induction are then distinguished: the inference of generals from particulars (first degree induction), and the generalization of generalizations (second degree induction). Induction is claimed to play a role in the framing of modest empirical generalizations and in the extension of every sort of generalizations—not however in the invention of high-level hypotheses containing theoretical predicates. It is maintained, on the other hand, that induction by enumeration is essential in the empirical test of the lowest-level consequences of scientific theories, since it occurs in the drawing of “conclusions” from the examination of empirical evidence. But it is also held that the empirical test is insufficient, and must be supplemented with theorification, or the expansion of isolated hypotheses into theories. Refutation is not viewed as a substitute for confirmation but as its complement, since the very notion of unfavorable case is meaningful only in connection with the concept of positive instance. Although the existence of an inductive method is disclaimed, it is maintained that the various patterns of plausible reasoning (inductive inference included) are worth being investigated. It is concluded that scientific research follows neither the advice of inductivism nor the injunction of deductivism, but takes a middle course in which induction is instrumental both heuristically and methodologically, although the over-all pattern of research is hypothetico-deductive.

Pursuing a line of progression articulated by Prof. Quine, Dr. Pasch (Experience and the Analytic) argues that the analytic-synthetic distinction rests on mere convention. Further, that the use of this distinction by present day empiricists—especially the rational reconstructionists—has caused empiricism to take a departure from traditional empiricism. I observe, in opposition, 1) the natural language firmament is itself an amorphous construct, 2) the natural language might be the language of experience but not of empiricism, 3) the ideal language is tied to experience by primitives for what perceptually appears, and 4) if one claims the primitives must be tested in scientific inquiry, a case should be made for this philosophical position.

In his The Uses of Argument (Cambridge University Press, 1958), S. Toulmin presents serious charges against ordinary logical theory, e.g., that it does not distinguish between analytic or formally valid or conclusive or warrant-using arguments, that the distinction between premises and conclusion is a bad oversimplification, that “major premise” conceals the distinction between inference-warrant and inference-backings, that logicians have been mistakenly working under an ideal of geometrical form.

The paper argues that none of the charges is proven, that most of them cannot be proven, that Toulmin's new logic is at best only vaguely hinted at and that his suggestions are positively obscure or mistaken.

Experimental observations are often taken in order to assist in making a choice between relevant hypotheses ~H and H. The power of observations in this decision is here metrically defined by information-theoretic concepts and Bayes' theorem. The exact (or maximum power) of a new observation to increase or decrease Pr(H) the prior probability that H is true; the power of that observation to modify the total amount of uncertainty involved in the choice between ~H and H: the power of a new observation to reduce uncertainty toward the ideal amount, zero; all these powers are systematically shown to be exact metrical functions of

where the numerator is the likelihood of the new observation given H, and the denominator is the “expectedness” of the observation.