I propose an argument for the thesis that laws of nature are necessary in the sense of holding in all worlds sharing the properties of the actual world, on the basis of a principle I propose to call the Causal Criterion of Reality . The CCR says: for an entity to be real it is necessary and sufficient that it is capable to make a difference to causal interactions. The crucial idea here is that the capacity to interact causally - (...) or to contribute to determining causal interactions - is not only the ultimate metaphysical ground for the existence of an entity, but it also provides a criterion for determining the nature of that entity, i.e. its properties. The alternative is to conceive of laws of nature as contingent: they could be different from what they are like in the actual world, where that possibility is understood to be metaphysical, not only epistemic. For the sake of this paper, I shall accept Armstrong's thesis that laws of nature are relations between universals. I also follow Armstrong in the view that both the existence and the properties of particulars are metaphysically independent of the existence and identity of other particular. However, what is controversial and what I shall challenge is his thesis that universals are like particulars in the following respect: according to Armstrong, each universal is a logically distinct entity whose existence and identity is independent of the existence and identity of other universals. My aim in this paper is to show that the identity of a universal is entirely determined by its lawful relations to other universals. The crucial premise I use is the thesis that the CCR is a universal criterion, which applies both to particulars and universals. From the thesis that the identity of a universal is exclusively determined by laws, it follows that laws are necessary in the sense that they cannot differ without the universals they link also being different. This creates a difficulty for those authors who, as Armstrong, accept the CCR but nevertheless defend the view that laws are contingent. (shrink)

Two chief problems of the theory of knowledge are the question of meaning and the question of verification. The first question asks under what conditions a sentence has meaning, in the sense of cognitive, factual meaning. The second one asks how we get to know something, how we can find out whether a given sentence is true or false. The second question presupposes the first one. Obviously we must understand a sentence, i.e. we must know its meaning, before we can (...) try to find out whether it is true or not. But, from the point of view of empiricism, there is a still closer connection between the two problems. In a certain sense, there is only one answer to the two questions. If we knew what it would be for a given sentence to be found true then we would know what its meaning is. And if for two sentences the conditions under which we would have to take them as true are the same, then they have the same meaning. Thus the meaning of a sentence is in a certain sense identical with the way we determine its truth or falsehood; and a sentence has meaning only if such a determination is possible. (shrink)

I. Causal Thesis: Dispositions have a causal basis. II. Distinctness Thesis: Dispositions are distinct from their causal basis. III. Impotence Thesis: Dispositions are not causally active.

In this sequence of philosophical essays about natural science, the author argues that fundamental explanatory laws, the deepest and most admired successes of modern physics, do not in fact describe regularities that exist in nature. Cartwright draws from many real-life examples to propound a novel distinction: that theoretical entities, and the complex and localized laws that describe them, can be interpreted realistically, but the simple unifying laws of basic theory cannot.

Most laws are ceteris paribus (cp) laws: they say not that all Fs are G but only that All Fs are G all else being equal. Most philosophical accounts of laws, however, have focused on strict laws. This paper considers how some of the standard philosophical problems about laws change when we switch attention from strict to cp laws and what special problems these laws raise. It is argued that some cp laws do not simply reflect the complexity of the (...) world and the limitations of our minds. Correctly interpreted, they reveal the simplicity that underlies the complexity, a simplicity that it is without our cognitive powers to grasp. (shrink)

It is a traditional empiricist doctrine that natural laws are universal truths. In order to overcome the obvious difficulties with this equation most empiricists qualify it by proposing to equate laws with universal truths that play a certain role, or have a certain function, within the larger scientific enterprise. This view is examined in detail and rejected; it fails to account for a variety of features that laws are acknowledged to have. An alternative view is advanced in which laws are (...) expressed by singular statements of fact describing the relationship between universal properties and magnitudes. (shrink)

Two chief problems of the theory of knowledge are the question of meaning and the question of verification. The first question asks under what conditions a sentence has meaning, in the sense of cognitive, factual meaning. The second one asks how we get to know something, how we can find out whether a given sentence is true or false. The second question presupposes the first one. Obviously we must understand a sentence, i.e. we must know its meaning, before we can (...) try to find out whether it is true or not. But, from the point of view of empiricism, there is a still closer connection between the two problems. In a certain sense, there is only one answer to the two questions. If we knew what it would be for a given sentence to be found true then we would know what its meaning is. And if for two sentences the conditions under which we would have to take them as true are the same, then they have the same meaning. Thus the meaning of a sentence is in a certain sense identical with the way we determine its truth or falsehood; and a sentence has meaning only if such a determination is possible. (shrink)

This paper argues against the deductive reconstruction of scientific prediction, that is, against the view that in prediction the predicted event follows deductively from the laws and initial conditions that are the basis of the prediction. The major argument of the paper is intended to show that the deductive reconstruction is an inaccurate reconstruction of actual scientific procedure. Our reason for maintaining that it is inaccurate is that if the deductive reconstruction were an accurate reconstruction, then scientific prediction would be (...) impossible. (shrink)

Hume defined ‘cause’ three times over. The two principal definitions (constant conjunction, felt determination) provide the anchors for the two main strands of the modem empiricist accounts of laws of nature 1 while the third (the counter factual definition 2) may be seen as the inspiration of the nonHumean necessitarian analyses. Corresponding to the felt determination definition is the account of laws that emphasizes human attitudes, beliefs, and actions. Latter day weavers of this strand include Nelson Goodman, A. J. Ayer, (...) and Nicholas Rescher. In Fact, Fiction and Forecast Goodman writes: “I want to emphasize the Humean idea that rather than a sentence being used for prediction because it is a law, it is called a law because it is used for prediction” (1955, p. 62). In “What is a law of nature?”, Ayer explains that the difference between ‘generalizations of fact’ and ‘generalizations of law’ “lies not so much on the side of facts which make them true, as in the attitude of those who put them forward” (1956, p. 162). And in a similar vein, Rescher maintains that lawfulness is “mind-dependent”; it is not something which is discovered but which is supplied: “Lawfulness is not found in or extracted from the evidence but superadded to it. Lawfulness is a matter of imputation” (1970, p. 107). By contrast, the constant conjunction definition promotes the view that laws are to be analyzed in terms of the de re characteristics of regularities, independently of the attitudes and actions of actual or potential knowers. (shrink)

Many philosophers insist that any adequate philosophical account of laws of nature must be consistent with Humean supervenience about the nomic . This is the thesis that the facts about the laws of nature must supervene on the particular, occurrent facts about the actual world. Earman argues that Humean supervenience poses an "empiricist loyalty test on laws." I concur, for as I argue, consistency with Humean supervenience is a necessary condition for upholding a plausible minimal empiricism concerning the methodology of (...) science. Other philosophers, such as Carroll, argue that no adequate account of laws could be consistent with Humean supervenience. Roughly the first half of the dissertation is devoted to refuting this pessimistic claim. Along the way, I show that two putative knock-down arguments against Humean supervenience are unsound , I show how Lewis's "Best-System Analysis" of laws can be remedied of its most prominent flaws while remaining true to Humean supervenience, and I criticize the "Universals Account" of laws defended by Armstrong, Dretske and Tooley. ;In the second half of the dissertation, I present and defend a novel account of laws of nature that is consistent with Humean supervenience. The basic idea behind this account is that a law of nature is a proposition that must be presupposed by any theoretical account of the reliability of any method of measuring some physical quantity. I argue that this account enjoys the advantages alleged for all other extant accounts of laws while avoiding many of their flaws. ;While my account is consistent with the thesis of Humean supervenience, I argue that it need not be interpreted as a Neo-Humean account in any interesting sense. Finally, I discuss the significance of Humean supervenience in a context where Neo-Humeanism is rejected. (shrink)

David Lewis's best-system analysis of laws of nature is perhaps the best known sophisticated regularity theory of laws. Its strengths are widely recognized, even by some of its ablest critics. Yet it suffers from what appears to be a glaring weakness: It seems to grant an arbitrary privilege to the standards of our own scientific culture. I argue that by reformulating, or reinterpreting, Lewis's exposition of the best-system analysis, we arrive at a view that is free of this weakness. The (...) resulting theory of laws has the surprising consequence that the term "law of nature" is indexical. (shrink)

In this volume, John Bacon argues that it is difficult to deny the existence of particularized properties and relations, which in modern philosophy are sometimes called `tropes'. In so doing, he advances a powerful and sophisticated metaphysical theory according to which both ordinary particulars and properties and relations are bundles of tropes.

This paper develops an account of explanation in biology which does not involve appeal to laws of nature, at least as traditionally conceived. Explanatory generalizations in biology must satisfy a requirement that I call invariance, but need not satisfy most of the other standard criteria for lawfulness. Once this point is recognized, there is little motivation for regarding such generalizations as laws of nature. Some of the differences between invariance and the related notions of stability and resiliency, due respectively to (...) Sandra Mitchell and Brian Skyrms, are explored. (shrink)