This paper examines commonly offered arguments to show that human behavior is not deterministic because it is not predictable. These arguments turn out to rest on the assumption that deterministic systems must be governed by deterministic laws, and that these give rise to predictability “in principle” of determined events. A positive account of determinism is advanced and it is shown that neither of these assumptions is true. The relation between determinism, laws, and prediction in practice is discussed as a question in scientific epistemology.

This paper considers objections to Popper's views on scientific method. It is argued that criticism of Popper's views, developed by Kuhn, Feyerabend, and Lakatos, are not too damaging, although they do require that Popper's views be modified somewhat. It is argued that a much more serious criticism is that Popper has failed to provide us with any reason for holding that the methodological rules he advocates give us a better hope of realizing the aims of science than any other set of rules. Consequently, Popper cannot adequately explain why we should value scientific theories more than other sorts of theories; which in turn means that Popper fails to solve adequately his fundamental problem, namely the problem of demarcation. It is suggested that in order to get around this difficulty we need to take the search for explanations as a fundamental aim of science.

Achinstein, Putnam, and others have urged the rejection of the received view on theories (which construes theories as axiomatic calculi where theoretical terms are given partial observational interpretations by correspondence rules) because (i) the notion of partial interpretation cannot be given precise formulation, and (ii) the observational-theoretical distinction cannot be drawn satisfactorily. I try to show that these are the wrong reasons for rejecting the received view since (i) is false and it is virtually impossible to demonstrate the truth of (ii). Nonetheless, the received view should be rejected because it obscures a number of epistemologically important features of scientific theorizing. I show this by sketching an alternative analysis which reveals some of these features and gives a more faithful picture of scientific theorizing.

The claim that theoretical entities are not real, that they are merely convenient fictions, has been defended and attacked in diverse ways. This paper is concerned with only one defense of the fictionalist thesis and with a certain realist attack on it. The defense in question is that theories which prima facie make reference to theoretical entities can be revised in such a way that no such apparent reference is made by eliminating all occurrences of theoretical expressions. It will be argued here that there is a procedure for revising theories which meets certain minimal criteria of adequacy, contrary to arguments in the literature. Further, it will be argued that the existence of this procedure provides neither sufficient nor necessary support for the fictionalist thesis, that this procedure is not of significance in the dispute between the fictionalist and the realist. Whether or not the theoretical-nontheoretical distinction is viable is another story which will not be told here. It will be assumed for the sake of argument that such a distinction can be drawn.

Biological foundations of the psychoneural identity hypothesis are explicated and their implications discussed. “Consciousness per se” and phenomenal contents of consciousness per se are seen to be identical with events in the (unobserved) brain in accordance with Leibniz's Law, but only informationally equivalent to neural events as observed. Phenomenal content potentially is recoverable by empirical means from observed neural events, but the converse is not possible. Consciousness per se is identical with events which do not represent anything distal to sensory receptor-transducer systems. Thus, on the psychoneural identity hypothesis, consciousness per se comprises directly physical events-in-themselves rather than being a Euclidean representation of physical events as is the case for phenomenal content. After comparing consciousness per se to “onta,” a paradox is suggested: rather than being irreducible to physical reality, consciousness per se is the only experience congruent with the ultimate nature of physical reality as conceived by contemporary physics.

Three distinct things have been called “referential opacity,” causing some confusion. A noun position in a sentence may be opaque in three different ways: (1) substitutivity of identity may fail there, (2) quantifiers prefixed to the sentence may not be able to bind variables in that position, or (3) substitutivity of identity may fail when the singular nouns in question are read as having small scope. Some connections among these three types of opacity are examined.

In this paper, I consider a variety of objections against the covering-law model of scientific explanation, show that Aristotle was already aware of them and had solutions for them, and argue that these solutions are correct. These solutions involve the notions of nonHumean causality and of essential properties. There are a great many familiar objections, both methodological and epistemological, to introducing these concepts into the methodology of science, but I show that these objections are based upon misunderstandings of these concepts.

Several philosophers of science have claimed that the conceptual difficulties of quantum mechanics can be resolved by appealing to a particular interpretation of probability theory. For example, Popper bases his treatment of quantum mechanics on the propensity interpretation of probability, and Margenau bases his treatment of quantum mechanics on the frequency interpretation of probability. The purpose of this paper is (i) to consider and reject such claims, and (ii) to discuss the question of whether the ψ-function refers to an individual system or to an ensemble of systems.

In the first part of this paper, two arguments, one by Chomsky, and one by Bar-Hillel and Shamir, are examined in detail and rejected. Both arguments purport to show that the structure of English precludes its having a finite state grammar which correctly enumerates just the well formed sentences of English.

In the latter part of the paper I consider the problem of supporting claims about the structure and properties of a natural language when no grammar for the language has yet been accepted.

Projectible conditions are (roughly) those whose universal generalizations are con firmed by their positive instances. This paper proposes certain modifications to the above definition in order to capture the pre-analytic notion it is supposed to explicate. Then we investigate what logical operations, when performed on projectible conditionals, yield new projectible conditionals. A number of surprising theorems are proven, and these theorems indicate that few conditionals having complex antecedents and consequents are projectible. It is also shown that projectibility is not closed under contraposition, and this is proposed as a solution to the Paradox of the Ravens. Finally, a general conjecture is made concerning just what conditionals are projectible, and it follows from this conjecture that although most conditionals are not projectible, they can still be dealt with inductively, but in ways more complex than recognized by classical confirmation theory.

This paper tries to extend Hintikka's inductive logic so that we can confirm a causally necessary statement. For this purpose, a joint system of inductive logic and logic of causal modalities is constructed. This system can offer a plausible explication of the distinction between nomic and accidental universality, as well as a good formulation of a causal law. And the transition from actuality to causal necessity is construed, in this system, as essentially probabilistic; i.e. no statements about actuality can entail a necessary statement, but certain statements about actuality can single out a most probable causal law.

An axiomatization of the theory is presented based on an explication of the 1957 text. Twenty-five theorems are deduced from the seven postulates. An abstract test space for the theory is formulated and the operations for its practical testing discussed. Traditional experimentation with the theory seems generally concerned with few of its propositions and incapable of testing it.

What has been learned about logic by means of “uninterpreted” logistic systems can be supplemented by comparing the latter with systems which are more uninterpreted, as well as with others which are less uninterpreted than the well-known logistic systems. By somewhat extending the meaning of ‘uninterpreted’, I hope to establish certain claims about the nature of logistic systems and also to cast some light on the nature of “logic itself.”

My procedure involves looking at three major “degrees” of interpretation: first, systems uninterpreted both semantically and syntactically, second, systems uninterpreted semantically but not syntactically, and third, systems uninterpreted neither semantically nor syntactically. We shall be forced to limit ourselves to the truth-functional part of logic in this brief study. What are usually called uninterpreted systems can be seen on a continuum of “degrees” of interpretation, from ordinary reasoning at one extreme to a “thoroughly uninterpreted system” at the other.

“Logic itself” apparently lies nearer to the interpreted, deformalized end of the spectrum than to the uninterpreted, formalized end. Logic is not identical with any particular logistic system, but is that which the particular logistic systems aim to formalize or model or capture. I propose that it is that minimum set of logical, rather than syntactical, primitive terms, definitions, and rules which is needed to generate logically, rather than syntactically, the principles of ordinary reasoning as it is used by logicians in their metalinguistic discussions and informal proofs of metatheorems. This minimum set is somewhat larger than the primitive bases of most logistic systems; its truth-functional part is presented in the “Deformalized Logic” at degree twelve.

Ordinary linguistic practices, as well as such extraordinary ones as are exemplified in scientific accounts, involve reporting, evaluating, and describing. This essay shows how a systematic account of these activities may help to illuminate the study of “ordinary language” and, ultimately, of technical linguistic practices.

Recent discussion of the problem of the conclusive falsification of scientific hypotheses has generally regarded the Duhemian Thesis (D-Thesis) as both true and interesting [10] but has dismissed the claim that disconfirmed hypotheses can be retained in explanations of the disconfirming evidence as either trivial [3] or unargued [12]. This paper rejects these positions. First, the status, in the argument for the D-Thesis, of the claim that auxiliary assumptions are necessary for the derivation of evidential propositions from hypotheses is examined. It is concluded that depending on this status, the D-Thesis is either trivially true or unargued. Then the retention of contextually disconfirmed hypotheses is discussed. It is found that the use of such hypotheses in explanations of the disconfirming evidence is mediated by principles of scientific methodology. A new thesis is presented connecting the problem of conclusive falsification with changes in methodology. The argument for this thesis introduces a new analysis of methodological principles as inductive generalizations from scientific practice. Finally, the contribution of this analysis to the understanding of scientific change is described.

This paper discusses the controversy between philosophers of science (e.g. Grünbaum) and historians of science (e.g. Holton) regarding Einstein's discovery of STR. Although Holton is surely correct on the historical point that experimental results (especially the Michelson–Morley experiment) had little influence on Einstein's development of STR, this fact is not sufficient to establish his (and Polanyi's) claim that major scientific discoveries are primarily matters of private, nonspecifiable insights into physical reality. It is possible that Einstein's work was based primarily on non-empirical but nonetheless publicly discussable, objective considerations. And a more comprehensive survey of the discovery of STR shows that this was indeed the case and thus excludes STR as a supporting instance of Holton's and Polanyi's assertions of the primacy of “private science.”

A presentation showing how the statements which relate to microphysical objects as they are different from the statements of classical mechanics is made. The determinism of classical and of quantum-mechanical theories is qualified. A (crucial) distinction between causality and determinism is given. Detailed analyses of diffraction as a result of single and double-slit demonstrations point to paradoxes arising from the use of particle or wave models, respectively, for photons and electrons. The compromising wave-packet model is underscored. The meanings for the Psi-function and for |ψ|2 are presented, with an explanation of the limitations that arise from giving an interpretation of |ψ|2 as a probability. The meaning of ψ-waves is analyzed. A case is made for the ψ-function's describing a well-ordered list of betting odds, based on previous statistical experiences, for the different results of specific experiments of a microscopic object of study with macroscopic apparatus. The Schrödinger wave equation is evaluated for meaning and judged as a deterministic expression.

A belief common among philosophers and biologists alike is that Mendelian genetics has been or is in the process of being reduced to molecular genetics, in the sense of formal theory reduction current in the literature. The purpose of this paper is to show that there are numerous empirical and conceptual difficulties which stand in the way of establishing a systematic inferential relation between Mendelian and molecular genetics. These difficulties, however, have little to do with the traditional objections which have been raised to reduction.

Numerous criticisms of Adolf Grünbaum's account of conventions in physics have been published ([1], [2], [3], [4], [13]), and he has replied to most of them ([6], [8]). Nonetheless, there seem to me to be good reasons for offering further criticism. In the first place Grünbaum's philosophy seems to me at least partly an extrapolation of one aspect of the views on conventions developed by Reichenbach and others. Since I think many of the issues which Reichenbach attempted to settle in his various discussions of conventions in physics are genuine and important, and I also think that those aspects of his views on which Grünbaum has focused are among the least satisfactory, it seems important to suggest questions and answers about conventions in physics which may develop more satisfactory Reichenbachian themes. Secondly, Grünbaum's philosophy centers on a distinction, that between extrinsic and intrinsic properties and relations, which has never been made satisfactorily clear either by Grünbaum or by his critics. Until it is clarified we will remain unsure of just what he is claiming and why we should think it true or think it false. Finally, Grünbaum's replies to his critics, especially his most recent reply, [9], involve unusually important claims which fail to be buttressed by the arguments he gives. I have in mind such claims as that we can learn something important about the ontological status of properties and relations by examining descriptions of them, that on (what I take to be) the most straightforward and literal interpretation, the general theory of relativity is inconsistent, and that the foremost advocates of geometrodynamics, Clifford and Wheeler, were and are enmeshed in contradiction. My own view is that all of these claims are dubious or false, but I shall be less concerned with establishing their falsity than with discrediting the arguments offered for them.