Carl G. Hempel

A Purely Syntactical Definition of Confirmation

The concept of confirmation occupies a central position in the methodology of empirical science. For it is the distinctive characteristic of an empirical hypothesis to be amenable, at least in principle, to a test based on suitable observations or experiments; the empirical data obtained in a test—or, as we shall prefer to say, the observation sentences describing those data—may then either confirm or disconfirm the given hypothesis, or they may be neutral with respect to it. To say that certain observation sentences confirm or disconfirm a hypothesis, does not, of course, generally mean that those observation sentences suffice strictly to prove or to refute the hypothesis in question, but rather that they constitute favorable, or unfavorable, evidence for it; and the term “neutral” is to indicate that the observation sentences are either entirely irrelevant to the hypothesis, or at least insufficient to strengthen or weaken it.

Comments on Goodman's Ways of Worldmaking

1. Nelson Goodmans book and Hilary Putnams observations on it evoked in me vivid memories of the conception of empirical know ledge that was propounded by Otto Neurath of the Vienna Circle about 1930, and which contrasted sharply with the views held by other members of the Circle at that time. Neurath certainly cannot be claimed to have anticipated Good mans ideas with their very wide scope; moreover, there are also important differences in fundamentals. But there are striking similarities between some of the basic ideas informing the two conceptions, and it may be of interest to begin with a brief consideration of those similarities: this will illuminate some of the virtues of Goodmans ideas, but it will also afford me an oppor tunity to suggest the desirability of a certain supplementation of the account given in Ways of Worldmaking.

Vagueness and Logic

ed from a natural language, or when an artificial language is to be constructed which is to serve as an interpreted linguistic system for communicating empirical contents. Thus the question as to the influence of vagueness upon the validity of the principles of logic does not arise on the purely syntactical and semantical level of investigation, and no modification of the logical symbolism is necessary. This content downloaded from 157.55.39.124 on Wed, 20 Jul 2016 04:11:34 UTC All use subject to http://about.jstor.org/terms

A definition of "degree of confirmation"

1. The problem. The concept of confirmation of an hypothesis by empirical evidence is of fundamental importance in the methodology of empirical science. For, first of all, a sentence cannot even be considered as expressing an empirical hypothesis at all unless it is theoretically capable of confirmation or disconfirmation, i.e. unless the kind of evidence can be characterized whose occurrence would confirm, or disconfirm, the sentence in question. And secondly, the acceptance or rejection of a sentence which does represent an empirical hypothesis is determined, in scientific procedure, by the degree to which it is confirmed by relevant evidence. The preceding remarks, however, are meant only as accounts of methodological tendencies and are not intended to imply the existence of clear-cut criteria by means of which the scientist can decide whether-or, in quantitative terms, to what degree-a given hypothesis is confirmed by certain data. For indeed, no general and objective criteria of this kind are at present available; in other words, no general definition of the concept of confirmation has been developed so far. This is a remarkable fact in view of the importance of the concept concerned, and the question naturally suggests itself whether it is at all possible to set up adequate general criteria of confirmation, or whether it may not rather be necessary to leave the decision in matters of confirmation to the intuitive appraisal of the scientist. This latter alternative would be highly unsatisfactory; for firstly, it would clearly jeopardize the objectivity-in the sense of intersubjectivity-of scientific procedure. Secondly, it would run counter to a view of confirmation which is now widely accepted; according to this view, statements about confirmation assert nothing regarding an observers subjective appraisal of the soundness of a hypothesis; rather, they concern a certain objective relation between a hypothesis and the empirical evidence with which it is confronted; this relation depends exclusively on the content of the hypothesis and of the evidence, and it is of a purely logical character in the sense that once a hypothesis and a description of certain observational findings are given, no further empirical investigation is needed to determine whether, or to what degree, the evidence confirms the hypothesis; the decision is a matter exclusively of certain logical criteria which form the subject matter of a formal discipline which might be called inductive logic. Of course, the widespread acceptance of this view does not prove that it is sound and that the program implicit in it can acttually be carried out. The best-and perhaps the only-method of settling the issue seems to consist in actually constructing an explicit and general definition and theory of confirmation. To do this is the purpose of this article. It is intended to present in outline, and with emphasis on the general methodological issues, a theory of

Valuation and Objectivity in Science

The role of valuation in scientific research has been widely discussed in the methodological and philosophical literature. The interest in the problem stems to a large extent from the concern that value-dependence would jeopardize the objectivity of science. This concern is clearly reflected, for example, in Max Weber’s influential writings on the subject.1

Rudolf Carnap, Logical Empiricist

In studying the conceptual problems connected with any logically or philosophically interesting term, one of the very first questions we encounter concerns the different grammatical constructions in which it normally occurs (insofar as there is a non-trivial difference in meaning between them). Some distinctions between such constructions have figured prominently in recent philosophical literature. A case in point is Ryle’s emphasis on the distinction between knowing that and knowing how, to which I shall soon return. However, in most cases surprisingly little systematic work has been done to clear up the precise relations between the different constructions and their relative priorities. For instance, even though there are a great many books and articles on the concept of goodness and on the meaning of the word ‘good’ it seems to me that the interrelations of the different grammatical constructions in which it can occur are but imperfectly understood. Some of the most acute discussions of the meaning of ‘good’, for example those by Paul Ziff in Semantic Analysis and by Jerrold J. Katz in Philosophy of Language, concentrate almost exclusively on the use of the word ‘good’ in the construction ‘a good X’1 These authors do not ask whether this is a basic and irreducible construction for the relevant logical and philosophical purposes, or whether it can be analyzed in terms of other uses of ‘good’, for instance, the one exemplified by ‘It is good that’. I suspect that the latter is more fundamental than the use in the form ‘a good X’.

Turns in the evolution of the problem of induction

Since the days of Humes skeptical doubt, philosophical conceptions of the problem of induction and of ways in which it might be properly solved or dissolved have undergone a series of striking metamor phoses. In my paper, I propose to examine some of those turnings, which seem to me to raise particularly important questions about the nature of empirical knowledge and especially scientific knowledge. Many, but by no means all, of the statements asserted by empirical science at a given time are accepted on the basis of previously established evidence sentences. Humes skeptical doubt reflects the realization that most of those indirectly, or inferentially, accepted assertions rest on evidence that gives them no complete, no logically conclusive, support. This is, of course, the point of Humes obser vation that even if we have examined many occurrences of A and have found them all to be accompanied by B, it is quite conceivable, or logically possible, that some future occurrence of A might not be accompanied by B. Nor, we might add, does our evidence guarantee that past or present occurrences of A that we have not observed were or are accompanied by B, let alone that all occurrences ever of A are, without exception, accompanied by B. Yet, in our everyday pursuits as well as in scientific research we constantly rely on what I will call the method of inductive ac ceptance, or MIA for short: we adopt beliefs, or expectations, about empirical matters on logically incomplete evidence, and we even base our actions on such beliefs to the point of staking our lives on some of them. The problem of induction is usually understood as the question of what can be said in justification of this procedure. Any attempt to answer that question requires, first of all, a clear characterization of the method of inductive acceptance, presumably

Hans Reichenbach remembered

Hans Reichenbach’s far-ranging and influential contributions to epistemology and the philosophy of science will be acknowledged and appraised in many contexts on the occasion of the one-hundredth anniversary of his birth. The following pages, however, are simply meant to record some personal recollections of Reichenbach as he affected one of his many students.

Empirical Statements And Falsifiability

1. Object of this note. In his lively essay, “Between Analytic and Empirical,” (Philosophy, April 1957), Mr. J. W. N. Watkins challenges the empiricist identification of synthetic statements with empirical ones by arguing that there exists an important class of statements which are synthetic, i.e. not analytically true or false, and yet not empirical. I find Mr. Watkinss arguments very stimulating, but I do not think they provide a sound basis for his contention. In the present note, I wish to indicate what seem to me the principal flaws in Mr. Watkinss reasoning, and to make some additional comments on the issues raised by his discussion.