The nature of the connection between theory and observation has been a major source of difficulty for philosophers of science. It is most vexing for those who would reduce the terms of a theory to those of an observation language, e.g. Carnap, Braithwaite, and Nagel. Carnap's work, particularly his treatment of physical theories as partially interpreted formalisms, forms the point of focus of this paper. Carnap attempted to make the connection between theory and observation through correspondence postulates. It is pointed out that such postulates depend in critical ways upon theoretical truths. This particular type of theoretical dependence produces serious trouble for Carnap's approach. For reasons given it may make it untenable. Furthermore, this problem when generalized creates difficulty for any similar reductionist program. Not only is this kind of theoretical dependence pointed out, but more important, the logical conditions which produce it are revealed. In this way light is shed upon the formal characteristics of the notion of theory dependence, especially upon the way in which observation terms depend upon theories for their meaning.

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 :

Beauregard ([1], p. 488) claims that Bowman and I were mistaken in saying that “… if the empirical predictions of the Special Theory regarding clock transport are correct, [then] a slow transport definition of simultaneity can be constructed that is logically independent of any signal definition, but is in fact equivalent to the standard signal definition” ([2], p. 131) His objection is not to the empirical concordance of the two criteria, but to the claim that the two are logically independent. His argument is that we fail to take account of Winnie's Passage Time Principle ([4], p. 228), and that if due account is taken of this principle, then “the concordance between the two criteria is logically guaranteed by the synchrony-free factual core of the STR” ([1], p. 488). However, one cannot show that A is not logically independent of B by showing that it is not independent of B and C. Hence, Beauregard's argument fails against the quoted passage.

Professor Everett W. Hall's new book, Modern Science and Human Values, one of the most important to have appeared in the field of Value Theory in the last ten years, shares in rich measure the common characteristic of so many other “prolegomena” to the future discipline of values: it is almost maddeningly frustrating. It sees with crystal clearness the essence of the scientific method and describes it in brilliant detail, from Galileo to Einstein; but it fails to draw a positive moral for value theory. On the contrary, its thesis is thoroughly negative: although value must be known as thoroughly as fact if the world is to survive, the scientific method that has brought us knowledge of fact can never bring us knowledge of value. For fact and value are fundamentally different, fact is known by science in a way that excludes value, and hence, whatever may be the way by which value is to be known, it cannot be science. It is true, science has given the most powerful and incisive formulation to fact while value theory has done nothing of the sort for value. Value theory, therefore, must be brought up to the level of science, otherwise there is danger that we may perish under the impact of science. But how to bring this about, how to construct a value theory as powerful and as representative of value as science is of fact, that is the question which the book can only ask but not answer.

A recent proposal by Dr. W. H. McCrae, cosmologist and mathematician, to the effect that decisions between such cosmogonies as those of Hoyle and of Gamow are experimentally impossible by virtue of a general cosmological indeterminacy principle, is here examined and elaborated upon. Some comments on the “antinomies” in Kant's “Critique of Pure Reason” are made in reference to this principle as well as to the Heisenberg indeterminacy principle. If McCrae's principle is accepted, we will have moved a long way toward Kant's conclusion that a logically consistent understanding of an underlying “ultimate reality” is outside the confines of science—whatever one may think of Kant's own line of reasoning.

Horizons are frontiers between things observable and things unobservable. Even if such horizons exist we may extrapolate from observable to non-observable regions of the universe by

1. (a) using the laws of physics which tell us how a presently observable galaxy will evolve even when we can no longer observe it, and

2. (b) using the cosmological principle, which tells us that the physical situation beyond the horizon is by and large the same as the physical situation within the horizon.

It would be paradoxical to define the universe in terms of objects or events within a horizon because it is only in virtue of information about objects and events outside the horizon that we have reason to believe that the horizon exists.

When the student of logic is first initiated into the problem of the relation of implication as expressed by the hypothetical proposition, he enters into a portion of logic which seems to him an impenetrable jungle. Elementary statements of the meaning of implication, as he is acquainted with them, are so meagre that they have failed to give any indication of the problems and paradoxes involved. Adequate discussions, on the other hand, are so abstruse that the initiate is lost in their incomprehensibility, for these are issues discussed by the technical logicians largely among themselves. When one considers the important bearings implicit in the interpretation of implication, such a state of affairs is greatly to be deplored. Through a simple but adequate presentation of the meaning of a hypothetical proposition one may be led not only to an understanding of a fundamental paradox of logic but to the whole question of modal logic and of the philosophy of logic. It is my purpose in what follows to present as simply as possible the various interpretations of the meaning of implication and to show their relations to modal logic. Having done this I believe it will be possible to state the case in favor of material implication in a new light.

A large number of definitions of the concept “model” have been given by various authors in recent years. Thirty-seven definitions are listed by A. I. Uyemov in a recent monograph (see [9]). This list is somewhat one-sided since it contains a disproportionate number of references to the work of Soviet authors. However, most of the important definitions given by Western writers are included. I shall give three definitions, all of great generality, so that various types of models, replicas, maps, theories and, most importantly, cybernetic models, are included. The advantage of this high degree of generality, or all-inclusiveness, is that the task of the investigator of uses of models in science, is reduced to classifying the various types of models, their construction, function, and structure, thus avoiding indecisive arguments (historically important, of course) such as the Duhem–Campbell controversy, so perceptively discussed by Mary Hesse ([2], [3]).

What is operations research? What is sufficiently new about it to constitute it a “new science”? And how is it related to philosophy?

1. What it is. MOR's definition, based on Kittel's, runs as follows:

Operations research is a scientific method of providing executive departments with a quantitative basis for decisions regarding the operations under their control (7: 1.)

In this paper we show how a form of Maxwellian Demon can be interpreted as a computing automaton. We then point out some ways in which the Demon systems can be generalized, and briefly describe and discuss the properties of some of the corresponding automata. It is shown that a generalized Maxwell Demon system can carry out arbitrary Turing computations.

Finally, the association developed between classes of thermodynamic systems and classes of computational systems is employed to suggest approaches to some fundamental problems of the relationships between computation, the information obtained by computation, and energy.

Horwich argues that we should reject metaphysical realism, but that we can preserve semantic realism by adhering to a redundancy theory of truth and a confirmationist account of linguistic understanding. But the latter will give us semantic realism only if it allows that the truth-values of sentences may transcend our recognitional capacities, and this is possible only insofar as we covertly reintroduce metaphysical realism. In spite of its intuitive appeal, we should not endorse semantic realism, but this need not bear upon the tenability of scientific realism.

1. Foreword. Man's every act is an act of faith; generally, an unconscious faith; seldom, an examined faith; never, a faith that by taking thought could have been replaced by assured certainties. All this appears whenever we stop to “rationalize” our conduct. Whatever that conduct may have been, it can be made to appear reasonable only if some propositions are taken to be true, others false. Or, perhaps the more experienced and less exacting mind would feel the reasonableness of its actions to have been as well established as might be, if it could show the premises with which its acts were consistent to be more likely true than false; those with whose truth they were inconsistent, more likely false than true. Either way of putting it points to the one moral; namely, that, apart from incalculable chance, there is nothing but one's judgment in the matter of premises to determine all that one's life can come to know of fruition or frustration. Nothing, then, can be more important to any man than to do all he can to assure the soundness of his reasons for the faith that is in him; i.e. to test the weight of evidence supporting the working hypotheses on which he is willing to act. But to have considered the evidence for the hypotheses on which he has acted or is prepared to act, could be practically useful only to one who had in one way or another come by a sound idea of the evidence on which one should act, if one's actions are not to end in disappointment. The result at which a man's thought on this matter of evidence may have arrived, will constitute his theory of evidence; and the task of constructing the soundest possible theory of evidence is the undertaking of philosophy.