Reichenbach held that all scientific inference reduces, via probability calculus, to induction, and he held that induction can be justified. He sees scientific knowledge in a practical context and insists that any rational assessment of actions requires a justification of induction. Gaps remain in his justifying argument; for we can not hope to prove that induction will succeed if success is possible. However, there are good prospects for completing a justification of essentially the kind he sought by showing that while (...) induction may succeed, no alternative is a rational way of trying.Reichenbach's claim that probability calculus, especially via Bayes' Theorem, can help to exhibit the structure of inference to theories is a valuable insight. However, his thesis that the weighting of all hypotheses rests only on frequency data is too restrictive, especially given his scientific realism. Other empirical factors are relevant. Any satisfactory account of scientific inference must be deeply indebted to Reichenbach's foundation work. (shrink)

Frank Jackson's criticisms have helped me recognize some of the weaknesses in my proposed vindication of induction. The core of the argument I offered was that induction is the only method of predicting which is based in a nonarbitrary way on the facts. I still believe that this is so and that because of this property induction is the only reasonable way of predicting. However I now recognize defects in the argument by which I attempted to establish that the uniqueness (...) of this property to induction constitutes its justification. (shrink)

According to the Feigl–Reichenbach–Salmon–Schurz pragmatic justification of induction, no predictive method is guaranteed or even likely to work for predicting the future; but if anything will work, induction will work—at least when induction is employed at the meta-level of predictive methods in light of their track records. One entertains a priori all manner of esoteric prediction methods, and is said to arrive a posteriori at the conclusion, based on the actual past, that object-level induction is optimal. Schurz’s refinements largely solve (...) the notorious short-run problem. A difficulty is noted, however, related to short-run worries but based on localized disagreement about the past, a feature characteristic of real debates (especially early modern) involving induction in intellectual history. Given the evidence about past events, _unfiltered by induction_, meta-induction might support a partly non-inductive method—especially as judged by proponents of esoteric prediction methods, who presumably believe that their methods have worked. Thus induction is justified meta-inductively in contexts where it was uncontroversial, while not obviously justified in key contexts where it has been disputed. This objection, momentarily sensed by Reichenbach regarding clairvoyance, is borne out by the Stoics’ use of meta-induction to justify both science and divination and by ancient Hebrew examples of meta-induction. Schurz’s recently introduced criteria for acceptance of testimony play a crucial role in arriving at object-level induction using meta-induction, but one might question them. Given the need for judgment in accepting testimony, it is unclear that the subjectivity of Howson’s Bayesian answer to Hume’s problem is overcome. (shrink)

While disagreeing with some of the detail of my argument in [2] F. John Clendinnen accepts its conclusion, namely, that the vindication he proposed in [1] fails. I will thus confine myself to saying, very briefly, why I think the new vindication of induction that he sketches in [3] also fails.

In “Induction and Objectivity” [1], F. John Clendinnen puts forwards a vindication of induction. I wish to argue that the vindication fails. As Clendinnen's argument is complex and presents certain difficulties it is necessary and only fair to quote his summary of it.“I shall attempt to vindicate induction by showing that it is the only possible way of predicting that is objective, and further that, while objectivity is not a necessary condition for success in predicting, objective methods are the only (...) methods which we could have any possible reason to believe possessed a property which is a necessary condition for success. This property I will call ”concordance“. An objective method is one that ensures that all whose use it will agree in their conclusions.... To say that a method is concordant is simply to say that there are no contradictory conclusions drawn from it. A method could possess this property as a consequence of its being objective; but on the other hand it is possible for a method of predicting to be concordant merely by chance.If a predicting method is to be successful it must be concordant; for if there were a number of conflicting predictions made about the outcome of the one situation it would only be possible for one of them to be correct, and we should not describe as successful a method which had at least as many false applications as correct. Thus concordance is a necessary condition of success even in a single occasion of predicting. What, then is the relation between an objective and a concordant method?It would be possible to have a concordant method by chance; for example, if a method should never be used to make more than one prediction about the outcome of any one situation it would ipso facto be concordant. Alternatively, the different predictions of a non-objective method may by chance agree. Thus objectivity is not a necessary condition of concordance nor, consequently, of being a successful method. However, in selecting a satisfactory method of predicting we must ensure that it is concordant. If we choose an objective method we do ensure this. Further, there is no other way of doing this; for by definition any method which of its nature is concordant is objective. The possibility of a non-objective method being concordant depends on contingencies beyond the control of the method or of any particular person who adopts it; for it is always possible for others to adopt the same method and make predictions about the same situations.Thus, knowing that concordance is a necessary condition of a successful method and knowing that the only possible reason for expecting any method to be concordant is that it is objective, we may conclude that it is reasonable to adopt a method if it can be shown that it is the only objective method.“. (shrink)