A Purely Syntactical Definition of Confirmation

1. Objective of the paper. The concept of confirmAtion occupies a centra] position in the methodology of empirical scienc'e. For it is the distinctive characteristic of an empirical hypothesis to be am.enable, 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 S2:1y, 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, e.vidence for it; a.nd the term "neutral" is to indicate that the observation sentences are either entirely irrelevant to the hypothesis 1 or at least insufficie.nt to strengthen or weaken it. Ao~ precise definition of the concepts of confirmation, disconfirmation, a,nd neutrality ,vhich have just been loosely characterized appears to be indispen.sa,ble for an adequate treatment of several fundamental problems in the logic and nlethodology of emi)irical science; these problems include the elucidation of the logical structure of scientific tests, explanations, and predictions, the logical analysis of the so-called inductive method, and a rigorous statement and development of the operationalist and empiricist conceptions of meaning and knowledge. However, no general definition of the concept of confirlnation and of its correlates seems to have been developed so far; and the few rudimentary definitions in1plicit in recent methodological writings prove unsatisfactory in various respects (cf. section 3, end). It is the objective of this study to develop a general definition" of confirmation in purely logical tern1S. Confirmation ,viII be construed as a certain logical relationship which may be considered as an ideal model or a "rational reconstruction" of the concept of confirmation as it is used in the methodology of empirical acience. Apart from its relevance for the theory of science, the definition off confirmation here to be developed appears to be of interest also from the viewpoint of formal logic ; for it is of a purely syntactical character,3 and it establishes a relation analogous in various ways to the relation of consequence in its syntactical interpretation. In fact, confirmation will prove to be, in a certain