Four current accounts of theory reduction are presented, first informally and then formally: (1) an account of direct theory reduction that is based on the contributions of Nagel, Woodger, and Quine, (2) an indirect reduction paradigm due to Kemeny and Oppenheim, (3) an "isomorphic model" schema traceable to Suppes, and (4) a theory of reduction that is based on the work of Popper, Feyerabend, and Kuhn. Reference is made, in an attempt to choose between these schemas, to the explanation of (...) physical optics by Maxwell's electromagnetic theory, and to the revisions of genetics necessitated by partial biochemical reductions of genetics. A more general reduction schema is proposed which: (1) yields as special cases the four reduction paradigms considered above, (2) seems to be in better accord with both the canons of logic and actual scientific practice, and (3) clarifies the problems of meaning variance and ontological reduction. (shrink)

When the evidence leaves us with a choice among hypotheses of unequal strength, how is the choice to be made?Caution would counsel us to choose the weakest, the hypothesis that asserts the least, since it is the least likely to fail us later. But the principle of maximum safety quickly reduces to absurdity; for it always dictates the choice of a hypothesis that does not go beyond the evidence at all.

One of the most difficult and interesting problems of rational decision is the choice among possible diverging paths in theory construction and among competing scientific theories—i.e., systems of accurate testable hypotheses. This task involves many beliefs—some warranted and others not as warranted—and marks decisive crossroads. Suffice to recall the current conflict between the general theory of relativity and alternative theories of gravitation that account for the same empirical evidence, the rivalry among different interpretations of quantum mechanics, and the variety of (...) cosmological theories. They all account for the same observed facts although they may predict different kinds of as yet unknown facts; they are consequently, up to now, empirically equivalent theories even though they are conceptually different and may even involve different philosophical views—i.e., they are conceptually inequivalent. (shrink)

The title of this symposium, “Formal Simplicity as a Weight in the Acceptability of Scientific Theories,” to some people might seem to suggest that we are to be making positive proposals about how the concept of simplicity could be defined for formalized languages, defined so as to figure in a formalized theory of confirmation. I must confess at the start that I do not have any such ambitious object in view. I now feel, indeed, that premature formalizations have little power (...) to illuminate the philosophically interesting questions which cluster round the problem of the role of simplicity in scientific thinking. So in this short paper I wish merely to present some elementary considerations, not very novel ones, concerning the role which simplicity seems to me to play in our non-demonstrative reasoning about matters of empirical fact. Although many writers have sought to analyze the logical character of such reasoning, little unanimity has been attained in their over-all views; thus it is that though the considerations which I wish to present are elementary, they are not wholly uncontroversial. But because these matters are elementary in nature, I do feel it appropriate in discussing them to use homely examples of uncomplicated kinds, rather than elaborate examples drawn from the more sophisticated reaches of scientific theory; in doing so, I am taking it for granted that scientific inference as regards its logical character is fundamentally a refinement of everyday thinking, rather than a procedure of some essentially different nature. (shrink)

The fact that simplicity has been linked with induction by many philosophers of science, some of whom have proposed or supported criteria of “inductive simplicity,” means that the problem must be given some serious attention. I take “inductive simplicity” as a title, however, only by way of concession to these historical treatments, since it is precisely the burden of my paper to show that there is no such thing. So much for the conclusion. I shall spend the remainder of my (...) time arguing for it. (shrink)