In this paper, I elucidate the main points involved in the question of the non-triviality of the conventionality of simultaneity within the kinematics of special relativity. I argue that there is an important distinction to be made between the inherited component and the sui generis component of the conventionality of simultaneity. The factual core of the kinematics of special relativity is explored, and it is shown that the Round-Trip Clock Retardation effect obtains if, and only if Winnie's Passage Time Principle holds. Some consequences of this fundamental fact are then explored. In particular, Grünbaum's view that the epistemological conventionality of simultaneity is logically prior to the physical inter-frame relativity of simultaneity is found to be based largely on what I call the inherited component of the former. Finally, a question is raised as to the very self-consistency of the claim, made by Ellis and Bowman, that standard signal synchrony and slow-transport synchrony are logically independent. In some concluding remarks, the author's general agreement with Grünbaum's conception of bridled conventionalism is indicated.

Science progresses if we succeed in rendering the objects of scientific inquiry more comprehensively or more precisely. Popper tries to formalize this venerable idea. According to him the most comprehensive and most precise description of the world is given by the set T of all true statements. A hypothesis comes the closer to T, or has the more verisimilitude, the more true consequences and the fewer false consequences it implies. Popper proposes to order hypotheses by the inclusion relations between the sets of their true and of their false consequences (“truth contents” and “falsity contents”). A partial ordering would permit one to decide whether the substitution of theory t1 by t2 represents scientific progress. But because of the logical relations between the elements of the sets of logical consequences, or contents, false hypotheses cannot be compared. As our theories usually turn out to be false sooner or later, they can seldom be compared as to their verisimilitude and when they can, the result depends only on which theory implies the other and on their truth-values. Popper even tries to define a measure of verisimilitude on the partial ordering. It has to fail for the same reason. In addition he tries to relativize the concept of a content and fails. What is more, any attempt at defining a measure of better or worse correspondence to the whole truth must fail, as there is no justification for saying that any true primitive sentence asserts as much about reality as some other primitive sentence, or more.

Is it a “conceptual truth” or only a logically contingent fact that, in any given kind of case, an event x which asymmetrically causes (“produces”) an event y likewise temporally precedes y or at least does not temporally succeed y? A bona fide physical example in which the cause retroproduces the effect would show that backward causation is no less conceptually possible than forward causation. And it has been claimed ([9], p. 151; [4], p. 41) that in Dirac's classical electrodynamics (relativistic and non-relativistic), the preacceleration of charged particles before any forces are applied to them furnishes a genuine case of retrocausation by later forces.

An exposition of the pertinent physics furnishes the basis for arguing the following: Whereas the non-zero acceleration of a neutral NEWTONIAN mass particle is, of course, causally connected as such to the simultaneously applied non-zero force, the non-zero acceleration of a DIRACIAN charged particle is not causally connected at all as such to the applied forces. A fortiori, in Dirac's electrodynamics, the applied forces do not qualify asymmetrically as the causes of a non-zero acceleration as such; nor does a non-zero acceleration as such qualify as an effect produced by forces. This is shown by means of two considerations as follows: (1) In Dirac's theory, no functional dependence of the value of a non-zero acceleration on the weighted time-average of the forces is vouchsafed as a matter of physical LAW alone without any value of a constant of integration, just as no Newtonian law(s) alone can guarantee a functional dependence of the non-zero value of the velocity of a Newtonian mass particle on the applied forces. Instead, both functional dependencies alike are vouchsafed only with the crucial aid of some de facto boundary condition pertaining to either the past or to the future, so that (2) Non-zero preaccelerations of Diracian charged particles can no more be causally attributed as such to the retrocausal action of later forces than non-zero “prevelocities” of Newtonian mass particles can be held to be caused as such by later applied forces. The retrocausal interpretation of Dirac's preaccelerations is just as invalid as the retrocausal interpretation of Newtonian prevelocities.

Several variant “Newtonian” theories of inertia and gravitation are described, and their scientific usefulness discussed. An examination of these theories is used to throw light on traditional epistemological and metaphysical questions about space and time. Finally these results are examined in the light of the changes induced by the transition from “Newtonian” to general relativistic spacetime.

In considering the possibility that the fundamental particles of matter might violate Leibniz's Principle, one is confronted with logical proofs that the Principle is a Theorem of Logic. This paper shows that the proof of that theorem is not universal enough to encompass entities that might not be unique, and also strongly suggests that photons, for example, do violate Leibniz's Principle. It also shows that the existence of non-individuals would imply the breakdown of Quine's criterion of ontological commitment.

A minimal second order modal logic of natural kinds is formulated. Concepts are distinguished from properties and relations in the conceptual-logistic background of the logic through a distinction between free and bound predicate variables. Not all concepts (as indicated by free predicate variables) need have a property or relation corresponding to them (as values of bound predicate variables). Issues pertaining to identity and existence as impredicative concepts are examined and an analysis of mass terms as nominalized predicates for kinds of stuff is proposed. The minimal logic is extendible through a summum genus, an infima species or a partition principle for natural kinds.

A theory of temporal passage is put forward which is “objective” in the sense that time flow characterizes the universe independently of the existence of conscious beings. The theory differs from Grünbaum's “mind-dependence” theory, and is designed to avoid Grünbaum's criticisms of an earlier theory of Reichenbach's. The representation of temporal becoming is accomplished by the introduction of indeterministic universe-models; each model representing the universe at a time. The models depict the past as a single four-dimensional manifold, and the future as a branched structure of such manifolds. Time flow is relativistic in that it manifests itself in a frame-dependent (but not observer-dependent) way. The indeterministic character of the universe-models is mirrored in a “temporal” theory of truth which rejects the principle of bivalence, and suitable semantics are provided for this theory. Finally, an account of physical law is given which defines it in terms of physical possibility, rather than vice versa.

In this paper I argue that human pattern recognition can be simulated by automata. In particular, I show that gestalt recognition and recognition of family resemblances are within the capabilities of sufficiently complex Turing machines. The argument rests on elementary facts of automata and computability theory which are used to explicate our preanalytic, informal concepts concerning gestalt patterns and recognition. The central idea is that of a machine which “knows” its own structure. Although the paper thus aims to support mechanism, especially as a framework hypothesis for perception, it contains suggestions for philosophy of science and philosophy of language as well. Some of these suggestions are sketched in the final section.

In this paper Rudolf Carnap's definition of ‘analytic truth’ based upon a meaning postulate At, for theoretical predicates of a given scientific theory is subjected to critique. It is argued that this definition is both too exclusive and too inclusive. Assuming that the preceding is correct, At is subjected to further scrutiny to determine how to interpret it and whether, and under what conditions, it need even be true. It is argued that a given At need not be true as a sentence in a scientific theory and that it must be regarded as a confusedly presented rule for the same. It is then argued that even as a semantical rule for the theory, At cannot provide a guarantee of truth for some meaning postulate similar to At in the theory itself. It is thus argued that Carnap's definition of ‘analytic truth’ for theoretical predicates is unsatisfactory.

This paper attempts to place Goodman's “New Riddle of Induction” within the context of a subjectivist understanding of inductive logic. It will be argued that predicates such as ‘grue’ cannot be denied projectible status in any a priori way, but must be considered in the context of a situation of inductive support. In particular, it will be argued that questions of projectibility are to be understood as a variety of questions about the ways a given sample is random. Various examples are considered, including cases when ‘grue’ (as opposed to 'green') should be projected, and some remarks are offered on what is meant when it is claimed that a sample is random (in ways relevant to inductive support) and how such randomness is determined. The view presented helps to make clear the relation between such apparently non-projectible predicates as 'grue' and the concept of being examined.

The use of negative probabilities is discussed for certain problems in which a stochastic process approach is indicated. An extension of probability theory to include signed (negative and positive) probabilities is outlined and both philosophical and axiomatic examinations of negative probabilities are presented. Finally, a class of applications illustrates the use and implications of signed probability theory.

B. F. Skinner's claim that “operant behavior is essentially the field of purpose” is systematically explored. It is argued that Charles Taylor's illuminating analysis of the explanatory significance of common-sense goal-ascriptions (1) lends some (fairly restricted) support to Skinner's claim, (2) considerably clarifies the conceptual significance of differences between operant and respondent behavior and conditioning, and (3) undercuts influential assertions (e.g., Taylor's) that research programs for behavioristic psychology share a “mechanistic” orientation. A strategy is suggested for assessing the plausibility of Skinner's broader claims about the adequacy of the operant behaviorist program for the analysis of purposive behavior.

The epistemological status of semantic components of ethnosemantics is investigated with reference to Wittgenstein's definition of the meaning of a word as its use in language. Semantic components, like the intension of words in logistic philosophy, constitute the conditions which must pertain to objects in order that they are denoted by particular words. “Componential meaning” is determined to be another form of “unitary meaning” and hence subject to the same critical arguments made by Wittgenstein against the latter's three fundamental types: (1) meanings are objects, (2) meanings are images, and (3) meanings are feelings and mental experiences. A rebuttal to D'Andrade's labeling rule objection to the usage theory of meaning is presented.

In order that a degree-of-belief function be coherent it is necessary and sufficient that it satisfy the axioms of probability theory. This theorem relies heavily for its proof on the two-valued sentential calculus, which emerges as a limiting case of a continuous scale of truth-values. In this “continuum of certainty” a theorem analogous to that instanced above is proved.

In this paper I shall be concerned primarily with contingent subjunctive conditionals, not to analyze them, but to argue that those who attempt such an analysis employing the concept of law—an approach which I confess seems promising—are at best providing logically sufficient conditions for the truth of contingent subjunctive conditionals and are not providing a correct analysis. My argument will have two parts. I shall first argue that the more plausible attempts to analyze our concept of law without subjunctive conditionals seem to fall prey to counter-examples. Secondly, I shall argue that even if we had an independent understanding of law, it is at least questionable that such an analysis could be employed in explicating conditions which are both logically necessary and sufficient for the truth of a subjunctive conditional.

The theory of the economics of research played a central role in the analysis of scientific method of Charles Sanders Peirce. The present paper describes Peirce's project as he saw it and then puts its machinery to work in an analysis of current issues in the philosophy of science. The aim is to show that, even apart from their historical interest, Peirce's ideas on this subject have a substantial systematic interest.

Hilbert's program attempts to show that our mathematical knowledge can be certain because we are able to know for certain the truths of elementary arithmetic. I argue that, in the absence of a theory of mathematical truth, Hilbert does not have a complete theory of our arithmetical knowledge. Further, while his deployment of a Kantian notion of intuition seems to promise an answer to scepticism, there is no way to complete Hilbert's epistemology which would answer to his avowed aims.

I argue that 'c' occurs extensionally in 'c caused e' and 'D' occurs extensionally in 'c caused e because c is D'. I claim that this has been insufficiently appreciated because the two contexts are often run together and because it has not been clear that the description D of c is among the referents of an explanatory argument. I argue as well that Hume's analysis of causation is consistent with taking causation to be a relation between single events, and that even if events are eliminated as virtual entities, extensionality holds for all terms in the resulting context.