Summary Canfield and Lehrer argued in [1] that it is impossible to predict an event deductively from given laws and initial conditions. In [2] I showed (1) that there are counterexamples to C&L's claim, (2) that their argument was based on an assumption which they failed to recognize, let alone support (the assumption that there are ‘rejectible’ facts), (3) that if certain simple conditions on predictability were granted, it could be shown that C&L's tacit assumption is false. In a recent (...) issue of this Journal Dr. Harnatt has criticized (3) (ignoring (1) and (2)), and he has concluded that we should still wonder whether there are any deductive predictions. Dr. Harnatt's arguments are shown to be defective. (shrink)

Laws of nature take center stage in philosophy of science. Laws are usually believed to stand in a tight conceptual relation to many important key concepts such as causation, explanation, confirmation, determinism, counterfactuals etc. Traditionally, philosophers of science have focused on physical laws, which were taken to be at least true, universal statements that support counterfactual claims. But, although this claim about laws might be true with respect to physics, laws in the special sciences (such as biology, psychology, economics etc.) (...) appear to have—maybe not surprisingly—different features than the laws of physics. Special science laws—for instance, the economic law “Under the condition of perfect competition, an increase of demand of a commodity leads to an increase of price, given that the quantity of the supplied commodity remains constant” and, in biology, Mendel's Laws—are usually taken to “have exceptions”, to be “non-universal” or “to be ceteris paribus laws”. How and whether the laws of physics and the laws of the special sciences differ is one of the crucial questions motivating the debate on ceteris paribus laws. Another major, controversial question concerns the determination of the precise meaning of “ceteris paribus”. Philosophers have attempted to explicate the meaning of ceteris paribus clauses in different ways. The question of meaning is connected to the problem of empirical content, i.e., the question whether ceteris paribus laws have non-trivial and empirically testable content. Since many philosophers have argued that ceteris paribus laws lack empirically testable content, this problem constitutes a major challenge to a theory of ceteris paribus laws. (shrink)

I propose a realist theory of laws formulated in terms of tropes that avoids both the problems of the "best-systems-analysis" and the "inference problem" of realism of universals. I analyze the concept of an exceptional situation, characterized as a situation in which a particular object satisfies the antecedent but not the consequent of the regularity associated with a law, without thereby falsifying that law. To take this possibility into account, the properties linked by a law must be conceived as dispositional (...) and not necessarily manifest. (shrink)

, Pietroski and Rey ([1995]) suggested a reconstruction of ceteris paribus (CP)-laws, which — as they claim — saves CP-laws from vacuity. This discussion note is intended to show that, although Pietroski and Rey's reconstruction is an improvement in comparison to previous suggestions, it cannot avoid the result that CP-laws are almost vacuous. It is proved that if Cx is an arbitrary (nomological) event-type which has independently identifiable deterministic causes, then for every other (nomological) event-type Ax which is not strictly (...) connected with Cx or with ¬Cx, ‘CP if Ax then Cx’ satisfies the conditions of Pietroski and Rey for CP-laws. It is also shown that Pietroski and Rey's reconstruction presupposes the assumption of determinism. The conclusion points towards some alternatives to Piectroski and Rey's reconstruction. (shrink)

The problem of ceteris paribus clauses and Hempel’s problem of provisos are closely-related difficulties. Both challenge advocates of accounts of scientific theories involving laws understood as universal generalizations, and they have been treated as identical problems. Earman and Roberts argue that the problems are distinct. Towards arguing against them, I characterize the relationship between Hempel’s provisos and one way of expressing ceteris paribus clauses. I then describe the relationship between the problems attributed to the clauses, suggesting that they form a (...) single problem-cluster. However, Hempel’s way of formulating provisos and discussing what they involve entangles provisos with the problem of skepticism. This creates a departure in Hempel’s discussion of provisos from the distinctive problem of vacuity which characterizes the problem of ceteris paribus clauses, though for different reasons than Earman and Roberts suggest. (shrink)

Summary Influenced by the account of K. Popper and, moreover, of C. G. Hempel and P. Oppenheim, it is generally assumed, that a prediction can be logically deduced from hypotheses, i. e. lawlike propositions, and initial conditions. It is not clear, in which respect a prediction can correctly be supposed to be a proposition which is either true or false. From a logical point of view, serious difficulties arise in assuming that the deductive-nomological model consists of a valid argument. Further (...) objections to this account are developed with regard to lawlike propositions. Since a lawlike proposition is — by definition — not true or definitely true, but only supposed to be true, it cannot function as a true premise among other true premises for the purpose of deduction. Special difficulties arise with regard to predictions: A predictive argument does not give any reason for the truth of the predictionK, but only — if at all — for the prediction of the truth ofK. In the latter case, the conclusion K clearly does not consist of a proposition (which could be either true or false) but rather of a predicting proposition. (shrink)

The paper focuses on interpreting ceteris paribus conditions as normal conditions. After discussing six basic problems for the explication of normal conditions and seven interpretations that do not well solve those problems I turn to what I call the epistemic account. According to it the normal is, roughly, the not unexpected. This is developed into a rigorous constructive account of normal conditions, which makes essential use of ranking theory and in particular allows to explain the phenomenon of multiply exceptional conditions. (...) Finally, this static account is extended to a schematic dynamic model of how we may learn about those normal and exceptional conditions. (shrink)

This paper is a supplement to, and provides a proof of principle of, Kuhn vs. Popper on Criticism and Dogmatism in Science: A Resolution at the Group Level. It illustrates how calculations may be performed in order to determine how the balance between different functions in science—such as imaginative, critical, and dogmatic—should be struck, with respect to confirmation (or corroboration) functions and rules of scientific method.

Hempel and Giere contend that the existence of provisos poses grave difficulties for any regularity account of physical law. However, Hempel and Giere rely upon a mistaken conception of the way in which statements acquire their content. By correcting this mistake, I remove the problem Hempel and Giere identify but reveal a different problem that provisos pose for a regularity account — indeed, for any account of physical law according to which the state of affairs described by a law-statement presupposes (...) a Humean regularity. These considerations suggest a normative analysis of law-statements. On this view, law-statements are not distinguished from accidental generalizations by the kind of Humean regularities they describe because a law-statement need not describe any Humean regularity. Rather, a law-statement says that in certain contexts, one ought to regard the assertion of a given type of claim, if made with justification, as a proper way to justify a claim of a certain other kind. (shrink)

According to Hempel, all scientific explanations and predictions which are produced exclusively with deterministic laws must be deductive, in the sense that the explanandum or the prediction must be a logical consequence of the laws and the initial conditions in the explanans. This deducibility thesis has been attacked from several quarters. Some time ago Canfield and Lehrer presented a “refutation” of DT as applied to predictions, in which they tried to prove that “if the deductive reconstruction [DT for predictions] were (...) an adequate reconstruction, then scientific prediction would be impossible”. Their argument seems to have been uncontested except for an inconclusive rejoinder by Beard. Moreover, Stegmüller has recently argued that “it may turn out that all or at least most of the so-called deductive-nomological explanations are in truth inductive and not deductive arguments, in view of the difficulty which has been pointed out by Canfield and Lehrer”. It seems it would be worth investigating whether Canfield and Lehrer's argument is, indeed, correct. (shrink)

This paper is a supplement to, and provides a proof of principle of, Kuhn vs. Popper on Criticism and Dogmatism in Science: A Resolution at the Group Level. It illustrates how calculations may be performed in order to determine how the balance between different functions in science—such as imaginative, critical, and dogmatic—should be struck, with respect to confirmation functions and rules of scientific method.