Though one believes that P is true, one can have reasons for thinking it false. Yet, it seems that one cannot know that P is true and (still) have reasons for thinking it false. Why is this so ? What feature of knowledge (or of reasons) precludes having reasons or evidence to believe (true) what you know to be false? If the connection between reasons (evidence) and what one believes is expressible as a probability relation, it would seem that the only satisfactory explanation of this fact is that when one knows that P is true, the reasons or evidence one has in support of P are such as to confer upon P the probability of 1. It is shown by an application of Bayes' Theorem that any value smaller than 1 would permit having reasons to believe what one knows to be false. Hence, it would seem that knowledge requires conclusive reasons to believe (if reasons or evidence is required at all).

I criticize the particular argument for evolutionary progressivism which is based on the concept of a series of “dominant life forms.”

My procedure is to show that there is no rigorous definition for the concept of “dominant life form.”

I examine several attempts to define this concept by Julian Huxley and a new formulation of the concept by G. G. Simpson and show that none of the criteria either of these men develop for determining which groups of organisms can be classified as dominant are adequate to exclude any groups of organisms from the classification. The concept proves so broad as to be meaningless. Since it is a key concept in the particular argument for progressivism that I discuss, the criticism of the concept demonstrates the argument to be invalid.

A serious problem for covering law explanation is raised and its consequences for the Hempelian theory of explanation are discussed. The problem concerns an intensional feature of explanations, involving the manner in which theoretical law statements are related to the events explained. The basic problem arises because explanations are not of events but of events under descriptions ; moreover, in a sense, our linguistic descriptions outrun laws. One form of the problem, termed the problem of weak intensionality, is apparently solved by a simple logical move, but in fact the problem arises in a new, strong form. It is found that Hempel's model for deductive explanation (to which this discussion is confined) requires modification to handle the weak intensionality problem but then is faced with the problem of strong intensionality. In consequence, it is suggested that Hempel's important concept of explanation sketch is not as widely applicable as usually claimed, especially for explanations in the behavioral and social sciences and history. Reason is found to reject the covering law thesis that every scientific explanation must contain at least one law statement. An important feature of the discussion is that some of the main reasons given for altering the deductive model and for considering other forms of explanation are internal to the covering law theory.

The Bohr-Heisenberg doctrine of wave-particle duality has been attacked in the past for its methodical defects, over-complication, internal contradictions, its positivistic phenomenalism, etc. The present investigation shows that duality, the doctrine of equivalence of the particle picture and the wave picture of matter, is untenable since its wave part leads to empirically wrong results in the relativistic domain, and violates the postulate of independence of the arbitrary choice of reference system in the non-relativistic realm. Therefore, when methodical objections were never quite conclusive, the physical failure of the duality idea seals its fate irrefutably, together with all its pseudo-philosophical implications.

In order to account for the actual function of analogue models in extending theories to new domains, we argue that it is necessary to analyze the inference involved into a complex two dimensional form. This form must go horizontally from descriptions of entities used as a model to redescriptions of entities in the new domain, and it must go vertically from an observation language to a theoretical language having a different and exclusive logical syntax. This complex inference can only be intelligible if we interpret theoretical terms in a platonic manner, a la Körner.

The thesis of this paper is that in dealing with problems of “mind,” the philosopher of mind needs to be as well grounded in his relevant sciences (e.g. psychology, anthropology) as the philosopher of the physical sciences needs to be grounded in his relevant sciences (e.g. physics). The thesis of this paper is also that the psychological analysis of solipsism and the philosophical analysis are not independent (or at least not independent in all of their aspects), and that therefore the psychological analysis sheds light on the philosophical, and vice versa. It is argued that solipsism is untenable on at least two grounds: because (1) there are no such physical phenomena as acts of “immediate perception,” and because (2), that there can be no such thing as an “individual mind” without some form of a “group mind.”

This essay discusses the problem of the two cultures. According to the author the problem arises because science is the source of a new way of conceiving reality and man, different from the mental conception entertained by nonscientific persons. The article suggests methodological guidelines for the philosopher interested in understanding the humanistic mentality of the scientists. The approach proposed is inductive-genetic. The aim is to help the philosopher explore science in its developmental becoming so that he may become aware of the reasons for the characteristic mentality of scientists as regards humanistic issues. The essay concludes with a discussion of the new perspectives disclosed to scientific-humanistic dialogue.

D. H. Sharp has recently argued that Einstein, Podolsky, and Rosen failed to make good their claim that elementary quantum theory provides only an incomplete description of physical reality. Sharp expounds in detail three criticisms (a fourth is mentioned) which focus largely on formal features of the quantum theory. I argue, on grounds centered largely in our search for an adequate physical understanding of the micro domain, that each of these criticisms must be rejected. The original criticism of quantum theory reemerges as a still-important baseline in our search for an adequate understanding of quantum theory.

Concepts originating in the philosophy of science generally are used only ritualistically and in careful isolation from research practice in political science. But philosophical considerations are fundamental to political research, and critically influence its decisions. The question is whether ideas offered by philosophers of science have practical (that is to say, theoretical) significance for political researchers. This essay argues that philosophy of science has extremely relevant ideas to offer. The argument proceeds through an initial presentation of some elementary notions drawn from reconstructions of the nature of concept formation-theory construction. These are then utilized in a critique of the research of quantitative political scientists. Three rather central concerns of this, still very young, discipline are discussed: measurement problems, the use of recursive and structural systems in causal modeling, and the primary logical function of multivariate analysis in political studies. The discussion is viewed as supporting the general point that applied philosophy of science ought to be, not an adjunct, but one of the key critical contributors to political research.

Thesis : Art like science radically affects our perceiving and thinking, and the two are substantially alike in that together—along with an inherited “natural” language system with which they overlap—they enable us to articulate the world.

Science has been advanced as the measure of all things: scientific realism. By implication, art pertains to beauty, science truth. Science effects conceptual breakthroughs, changes our models of natural order. On the contrary (I argue), as a nonverbal symbol system art similarly affects paradigm-induced expectations. Substantively there is no difference in the way each enables us to articulate or measure the world : symbolic realism.

The myth of resemblance as a criterion of representation—imitation as a one-one relation—has, at least since the time of Plato, obscured this truth. Once the distinction between representational and nonrepresentational art falls, the true nature of artist (like scientist) as maker is illumined. The artist, the scientist (disciplinarian), the cosmologist (those responsible for the formulation of so-called natural languages—in time all of us) make the world or, what practically amounts to the same thing, the known, perceived world. This is the claim of the symbolic realist. Is symbolic realism itself only a watershed ? What implication does this critique have for assessing the role of the philosopher today?

James Cornman has recently offered a definition for ‘observation term’ which he takes to meet most, if not all, of the standard objections to such definitions. He also employs this definition against certain materialists, but in what follows I wish only to address myself to the proposed definition. I shall argue that he has failed to show any logical difference between “observation terms,” as he defines them, and terms which are not so classified. I shall show that his definition is too restrictive.

In a recent paper in this journal which was part of a panel discussion of Grünbaum's philosophy of science, M. G. Evans discusses the Lorentz-Fitzgerald contraction hypothesis and related matters [2]. The purpose of this note is to clarify and correct some of the points in Evans' paper.

In the preceding article, [3], Peter Machamer states three objections to my recent attempt to define ‘observation term’. While I believe that all Machamer's objections are mistaken, as I will try to show, his discussion does touch on two problems which have forced revisions. Both his first and second objections are that my definition is too restrictive because its second necessary condition for a term ‘O‘ being an observation term rules out too many terms which are obviously observation terms. The condition is :

The claim that there are nonpurposive functional statements is critically examined by looking at nine translation schemata, several of which are drawn from recent literature. All but one or two fail, suggesting that all functional statements (a) are causal (and not about probabilities or necessary conditions), and (b) have implicit reference to goals. If so, then the possibility of nonpurposive functional statements rests squarely on the possibility of nonpurposive goals.