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)

Laws are supposed to tell us how physical systems actually behave. The analysis of an important part of physical practice--abstraction--shows, however, that laws describe the behavior of physical systems under very special circumstances, namely when they are isolated. Nevertheless, laws are applied in cases of non-isolation as well. This practice requires an explanation. It is argued that one has to assume that physical systems have dispositions. I take these to be innocuous from an empiricist's standpoint because they can--at least in (...) principle--be measured. Laws can be applied whenever such a disposition is present, they describe how the physical system would behave if the disposition were manifest. (shrink)

Das Buch verschafft einen Überblick über die neuere Willensfreiheitsdebatte, wobei es auch die Konsequenzen der Hirnforschung für das Freiheitsproblem erörtert. Ferner entwickelt der Autor eine eigene Position, die er 'fähigkeitsbasierten Libertarismus' nennt. Er widerspricht dem breiten philosophischen Konsens, dass jedenfalls eine Art von Freiheit mit einem naturwissenschaftlichen Weltbild unverträglich sei, nämlich die Fähigkeit, sich unter gegebenen Bedingungen so oder anders zu entscheiden. Im Buch wird argumentiert, dass der libertarischen Freiheitsauffassung, die wir im Alltag alle teilen, bei näherer Betrachtung keine Tatschen (...) entgegenstehen, sondern nur philosophische Doktrinen. Zwar können wir durch unser Handeln keine Naturgesetze abändern und sind auch keine ersten Beweger, aber für ein So-oder-Anderskönnen bedarf es dessen nicht. (shrink)

The biological sciences employ a concept of normality that must be distinguished from statistical or value concepts. The concept of normality is presupposed in the standard explications of biological functions, and it is crucial to the strategy of explanation by approximations in, for example, physiology. Nevertheless, this concept of normality does not seem to be captured in the language of physics. Thus attempts at explaining the methodological relationship between the biological sciences and the physical sciences by concentrating only on the (...) concept of biological function cannot go very far. An analysis of the concept of normality is also necessary. (shrink)

Recent work in the philosophy of science has been debunking theory and acclaiming practice. Recent work in philosophical psychology has been neglecting practice and emphasizing theory, suggesting that common?sense psychology is in all essential respects like any scientific theory. The marriage of these two strands of thought would serve to make science and common sense virtually indistinguishable. My paper resists this conflation. The main target is the attempt to assimilate everyday psychology to a scientific theory; I argue that this is (...) badly mistaken, and does a disservice both to scientific and to common?sense psychology. A secondary aim is to argue that some of the new pragmatism in the philosophy of science is overstated. The suggested conflation would have interesting implications, as would its denial; in a concluding section, some of these implications are briefly explored. (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)

You are asked to call out the letters on a chart during an eyeexamination: you see and then read out the letters ‘U’, ‘R’, and ‘X’. Commonsense says that your perceptual experiences causally control your calling out the letters. Or suppose you are playing a game of chess intent on winning: you plan your strategy and move your chess pieces accordingly. Again, commonsense says that your intentions and plans causally control your moving the chess pieces. These causal judgements are as (...) plain and evident as any can be. (shrink)

This paper has three goals. The first goal is to work out the difference between literal ceteris paribus laws in the sense of “all others being equal” and ceteris rectis “laws” in the sense of “all others being right”. While cp laws involve a universal quantification, cr generalizations involve an existential quantification over the values of the remainder variables Z. As a result, the two differ crucially in their confirmability and lawlikeness. The second goal is to provide a classification of (...) different kinds of cr generalizations, including certain transition cases between cr generalizations and cp laws. The third goal is to work out what cp laws and all kinds of cr assertions have in common: they figure as an information source for assertions of causal influence between variables. (shrink)

This paper explores the question: can fundamental dispositions (which have no distinct causal basis) suffer from finks and antidotes? I use my response to shed light on the question: can the fundamental laws of physics be ceteris paribus laws?

Dispositions are related to conditionals. Typically a fragile glass will break if struck with force. But possession of the disposition does not entail the corresponding simple (subjunctive or counterfactual) conditional. The phenomena of finks and antidotes show that an object may possess the disposition without the conditional being true. Finks and antidotes may be thought of as exceptions to the straightforward relation between disposition and conditional. The existence of these phenomena are easy to demonstrate at the macro-level. But do they (...) exist at the fundamental level also? While fundamental finkish dispositions may be excluded fairly straightforwardly, the existence of fundamental antidotes is more open. Nonetheless I conclude that the phenomenon is likely to be less widespread than at the macro level and that fundamental antidotes may be eliminable. According to the dispositional essentialist, the laws of nature can be explained by taking natural properties to be essentially dispositional. This account can be extended to show that the existence of finks and antidotes explains ceteris paribus laws. Consequently the existence or otherwise of fundamental finks and antidotes sheds some light on the question of whether fundamental laws may also be ceteris paribus laws. (shrink)

Two controversies exist regarding the appropriate characterization of hierarchical and adaptive evolution in natural populations. In biology, there is the Wright-Fisher controversy over the relative roles of random genetic drift, natural selection, population structure, and interdemic selection in adaptive evolution begun by Sewall Wright and Ronald Aylmer Fisher. There is also the Units of Selection debate, spanning both the biological and the philosophical literature and including the impassioned group-selection debate. Why do these two discourses exist separately, and interact relatively little? (...) We postulate that the reason for this schism can be found in the differing focus of each controversy, a deep difference itself determined by distinct general styles of scientific research guiding each discourse. That is, the Wright-Fisher debate focuses on adaptive process, and tends to be instructed by the mathematical modeling style, while the focus of the Units of Selection controversy is adaptive product, and is typically guided by the function style. The differences between the two discourses can be usefully tracked by examining their interpretations of two contested strategies for theorizing hierarchical selection: horizontal and vertical averaging. (shrink)

This paper examines the process of modelling a complex empirical phenomenon in modern astrophysics: extended extragalactic radio sources. I show that modelling is done piecemeal, addressing selected striking or puzzling features of that phenomenon separately and individually. The result is various independent and separate sub-models concerned only with limited aspects of the same phenomenon. Because the sub-models represent features of the same physical phenomenon, they need to be reasonably consistent with each other - a criterion not always fully adhered to (...) - and there needs to be a way to conceptually `re-unite' the sub-models to form an overall-model. Visualisation, that is, supplying a concrete interpretation of abstract, theoretical sub-models, aids this modelling process. My case study further endorses the view that modelling is `work in progress', i.e. a form of developing knowledge whereby models represent, not replicate, a phenomenon. (shrink)

The philosophical problem of mental causation concerns a clash between commonsense and scientific views about the causation of human behaviour. On the one hand, commonsense suggests that our actions are caused by our mental states—our thoughts, intentions, beliefs and so on. On the other hand, neuroscience assumes that all bodily movements are caused by neurochemical events. It is implausible to suppose that our actions are causally overdetermined in the same way that the ringing of a bell may be overdetermined by (...) two hammers striking it at the same time. So how are we to reconcile these two views about the causal origins of human behaviour? One philosophical doctrine effects a nice reconciliation. Neuralism, or the token-identity theory, states that every particular mental event is a neurophysiological event and that every action is a physically specifiable bodily movement. If these identities hold, there is no problem of causal overdetermination: the apparently different causal pathways to the behaviour are actually one and the same pathway viewed from different perspectives. This attractively simple view is enjoying a recent revival in fortunes. (shrink)

Questions concerning the epistemological status of computer science are, in this paper, answered from the point of view of the formal verification framework. State space reduction techniques adopted to simplify computational models in model checking are analysed in terms of Aristotelian abstractions and Galilean idealizations characterizing the inquiry of empirical systems. Methodological considerations drawn here are employed to argue in favour of the scientific understanding of computer science as a discipline. Specifically, reduced models gained by Dataion are acknowledged as Aristotelian (...) abstractions that include only data which are sufficient to examine the interested executions. The present study highlights how the need to maximize incompatible properties is at the basis of both Abstraction Refinement, the process of generating a cascade of computational models to achieve a balance between simplicity and informativeness, and the Multiple Model Idealization approach in biology. Finally, fairness constraints, imposed to computational models to allow fair behaviours only, are defined as ceteris paribus conditions under which temporal formulas, formalizing software requirements, acquire the status of law-like statements about the software systems executions. (shrink)

Kripke (Wittgenstein on rules and private language: an elementary exposition. Harvard University Press, Cambridge Mass, 1982 ) rejected a naturalistic dispositional account of meaning (hereafter semantic dispositionalism) in a skeptical argument about rule-following he attributes to Wittgenstein (Philosophical investigation. Basil Blackwell, Oxford, 1958 ). Most philosophers who oppose Kripke’s criticisms of semantic dispositionalism take the stance that the argument proves too much: semantic dispositionalism is similar to much of our respected science in some important aspects, and hence to discard the (...) former would mean to give up the latter, which is obviously wrong. In this paper, I shall discuss and reject a recent defense of Kripke by Kusch (Analysis 65(2):156–163 2005 ; Sceptical guide to meaning and rules: defending Kripke’s Wittgenstein. McGill-Queen’s, London, 2006 ). Kusch attempts to show that semantic dispositionalism differs from the sciences, and consequently, Kripke’s attack can only target semantic dispositionalism, but not the sciences. Specifically, Kusch identifies some important features of the sciences with regard to how it employs idealization and ceteris paribus clauses, and argues that the ways in which semantic dispositionalism uses them are dramatically different. I argue that, upon close examination, the two are more similar than otherwise in each of those features. (shrink)

This paper explores the question: can fundamental dispositions suffer from finks and antidotes? I use my response to shed light on the question: can the fundamental laws of physics be ceteris paribus laws?

There appear to be no biological regularities that have the properties traditionally associated with laws, such as an unlimited scope or holding in all or many possible background conditions. Mitchell, Lange, and others have therefore suggested redefining laws to redeem the lawlike status of biological regularities. These authors suggest that biological regularities are lawlike because they are pragmatically or paradigmatically similar to laws or stable regularities. I will review these re-definitions by arguing both that there are difficulties in applying their (...) accounts to biology and difficulties in the accounts themselves, which suggests that the accounts are not adequate to redeem the lawlike status of biological regularities. Finally, I will suggest a new account of laws that also shows how non-laws might function in some of the roles of laws. (shrink)

This paper develops an account of scientific objectivity for a relativist theory of evidence. It briefly reviews the character and shortcomings of empiricist and wholist treatments of theory acceptance and objectivity and argues that the relativist account of evidence developed by the author in an earlier essay offers a more satisfactory framework within which to approach questions of justification and intertheoretic comparison. The difficulty with relativism is that it seems to eliminate objectivity from scientific method. Reconceiving objectivity as a function (...) of the social character of science, rather than of individually practiced methods, allows us to claim that science is objective even if relativism is true, and provides a more realistic account of scientific objectivity than is possible on either the empiricist or the wholist accounts. (shrink)

Few have given an extended treatment of the non-statistical sense of normality: a sense captured in sentences like “dogs have four legs,” or “hammers normally have metal heads,” or “it is normal for badgers to take dust baths.” The most direct extant treatment is Bernhard Nickel’s Between Logic and the World, where he claims that the normal or characteristic for a kind is what we can explain by appeal to the right sorts of explanations. Just which explanatory strategies can ground (...) normalities, though, is difficult to determine without inviting circularity into the account. After raising this and other worries for Nickel’s account, I develop my own account according to which normal features are those which are explained by the kind of thing involved. (shrink)

Given that an analysis of disposition ascription cannot be made in terms of a simple subjunctive conditional, we present a multiply qualified conditional analysis that places disposition ascription within an implicit fundamental causal conceptual typography within which a disposition ascription is embedded, framed, and understood. By placing the multiply qualified analysis within an implicit causal matrix involving a focal cause, pathway of influence, mechanism of action, contributing/partial cause, mediator, extrinsic moderator,, intrinsic moderator, and manifestation, we show how this analysis evades (...) counterexamples and arguments raised against the simple conditional analysis. We then indicate how the causal conceptual landscape provides a roadmap for unpacking and explicating parameters of the ceteris paribus qualifier to acquit the analysis of charges of being vacuous or irredeemably vague. (shrink)

It is often argued that biological generalizations have a distinctive and special status by comparison with the generalizations of other natural sciences, such as that biological generalizations are riddled with exceptions defying systematic and simple treatment. This special status of biology is used as a premise in arguments that posit a deprived explanatory, nomological, or methodological status in the biological sciences. I will discuss the traditional and still almost universally held idea that the biological sciences cannot deal with exceptions and (...) application conditions of their generalizations with their own distinctive and proprietary explanantia, but need the help of lower-level sciences to carry out this task. The idea of lower-level explanations of exceptions is connected to the idea that the biological sciences need lower-level sciences to better themselves and to the idea that biological sciences cannot provide reliable and extrapolatable results or explanations by themselves. I present counterexamples to the idea of lower-level explanations of exceptions in biology. I also discuss and refute more general arguments why the idea of lower-level explanations of exceptions has been held to hold in the special sciences, such as the screening-off and openness arguments. This suggest that there might be nothing special about the biological sciences vis-à-vis the more fundamental natural sciences, such as physics insofar as explanations of exceptions are concerned, and that the biological sciences can provide reliable and extrapolatable results or explanations by themselves. (shrink)

One would have thought that Fodor's justly famous computational views about the mind and his covariation approaches to content owed a lot to the twentieth century that he now reviles. On the other hand, a number of lines he pursues in the target article make one wonder whether he hasn’t perhaps changed his mind about those famous views. Specifically, I argue that his own theory of content is open to the very same objections he raises against ‘sorting’ theories, and that (...) the supposed circularity in implicit definitions of logical particles can easily be avoided by the very functional/computational definitions that he fathered decades ago. Fodor's rejection here of sorting and implicit definition does make one worry that he is now opting for what seems the only atomistic alternative that would seem to be left, the first‐person meaning mysticism of the very Cartesian sort he now claims to favor, but from which I would have thought twentieth century role and discrimination views were a welcome relief. Despite all these worries, however, I concede that one could probably do worse than assume for the nonce that meaning is atomic, or, anyway, unanalyzed, and get on with investigating the mind on that basis—but keeping the options open. (shrink)

When is a law too idealized to be usefully applied to a specific situation? To answer this question, this essay considers a law in hydrogeology called Darcy''s Law, both as it is used in what is called the symmetric-cone model, and as it is used in equations to determine a well''s groundwater velocity and hydraulic conductivity. After discussing Darcy''s law and its applications, the essay concludes that this idealized law, as well as associated models and equations in hydrogeology, are not (...) realistic in the sense required by the D-N account. They exhibit what McMullin calls mathematical idealization, construct idealization, empirical-causal idealization, and subjunctive-causal idealization. Yet this lack of realism in hydrogeology is problematic for reasons unrelated to the status of the D-N account. These idealizations are also problematic in applied situations. Their problems require developing two supplemental criteria, necessary for their productive application. (shrink)

It has not been sufficiently considered in philosophical discussions of ceteris paribus (CP) laws that distinct kinds of CP-laws exist in science with rather different meanings. I distinguish between (1.) comparative CP-laws and (2.) exclusive CP-laws. There exist also mixed CP-laws, which contain a comparative and an exclusive CP-clause. Exclusive CP-laws may be either (2.1) definite, (2.2) indefinite or (2.3) normic. While CP-laws of kind (2.1) and (2.2) exhibit deductivistic behaviour, CP-laws of kind (2.3) require a probabilistic or non-monotonic reconstruction. (...) CP-laws of kind (1) may be both deductivistic or probabilistic. All these kinds of CP-laws have empirical content by which they are testable, except CP-laws of kind (2.2) which are almost vacuous. Typically, CP-laws of kind (1) express invariant correlations, CP-laws of kind (2.1) express closed system laws of physical sciences, and CP-laws of kind (2.3) express normic laws of non-physical sciences based on evolution-theoretic stability properties. (shrink)

After a brief survey of the literature on ceteris paribus clauses and ceteris paribus laws (1), the problem of exceptions, which creates the need for cp laws, is discussed (2). It emerges that the so-called skeptical view of laws of nature does not apply to laws of any kind whatever. Only some laws of physics are plagued with exceptions, not THE laws (3). Cp clauses promise a remedy, which has to be located among the further reactions to the skeptical view (...) (4). After inspecting various translations of the Latin term 'ceteris paribus' (5), the paper arrives at the conclusion that, on the most reasonable translation, there are no such things as cp laws, for reasons of logical form. Cp clauses have an indexical content, so that they need singular propositions as their habitat, not general ones. Cp clauses and the universal generalizations they are supposed to modify are not fit for each other (6). (shrink)

The apparent underdetermination of the formalism of quantum field theory (QFT) as between a particle and a field interpretation is studied in this paper through a detour over the problem of unifying QFT with general relativity. All we have at present is a partial or approximate unification, QFT in non-Minkowskian spaces. The nature of this hybrid and the problem of its internal consistency are discussed. One of its most striking implications is that particles do not have an observer-independent existence. We (...) trace the ways in which physicists reacted to this at first highly implausible ontological consequence. We conclude that quantum fields rather than particles are after all the basic entities in QFT. (shrink)

Terence Horgan and John Tienson claim that folk psychological laws are different in kind from basic physical laws in at least two ways: first, physical laws do not possess the kind of ceteris paribus qualifications possessed by folk psychological laws, which means the two types of laws have different logical forms; and second, applied physical laws are best thought of as being about an idealized world and folk psychological laws about the actual world. I argue that Horgan and Tienson have (...) not made a persuasive case for either of the preceding views. (shrink)

The logical empiricists knew that scientific theories sometimes arise out of the attempt to reconcile or unify two existing theories. They also thought that, at best, old theories would be retained as approximations to their successors. Kuhn lost both insights when he rejected the logical empiricists' formal approach in favor of an exclusively historical and psychological one. But when Putnam tried to restore such ideas he failed to provide them with the historical support they require. An account of revolutionary unifications (...) is defended as reconciling Putnam's realist ideas about methodology with Kuhn's historical approach. (shrink)

Science breaks new trails for technology but social science has yet to break new trails for social technology. Why is this? One hypothesis explains this with reference to the complexity of the social world and the still rudimentary nature of the social sciences. This paper argues for an alternative hypothesis, claiming that social science research is incapable of generating technologies not already part of the human repertoire. Drawing on a range of social science inquiry from economics to psychology, it shows (...) that the ?mechanisms? posited to explain normal and puzzling human behavior depend on familiar facts about humans which future investigations cannot overturn. Finally, it is shown that even when these familiar facts are themselves explained, the generative mechanisms posited to account for them are no longer within the sphere of the social sciences. (shrink)

The idea that science aspires to and routinely achieves truths about the world has been challenged in recent writings. Rather than beginning with a theory of scientific development, or of scientific explanation, we begin with a consideration of truth claims in ordinary discourse, particularly with Davidson's truth-functional semantics. Next we consider the way in which some framework features of ordinary language discourse are extended to and modified in scientific discourse. Two areas are treated in more detail: quantum theory, and the (...) peculiar problem of semantic entailment it involves; and quantum field theory. These supply a basis for criticizing some historicist and logicist treatments of the truth of scientific claims. (shrink)

The selected effects theory is supposed to provide a fully naturalistic basis for statements about what biological traits or processes are for without appeal to final causes or intelligent design. On the selected effects theory, biologists are allowed to say, for instance, that hindwing eyespots on butterfly wings serve to deflect predators’ attacks away from vital organs because a similar fitness-enhancing effect explains why eyespots themselves were favoured by natural selection and persisted in the population. This is known as the (...) explanatory dimension of the selected effects theory. According to it, appealing to the fitness-enhancing effect of a certain trait or process is sufficient to explain its current presence in a population, namely, why it persisted and still exists in that population. In this paper, however, I will call such a claim into question, and I will do so by discussing a mathematical Hawk-Dove example and a real case scenario taken from evolutionary biology, that of Perissodus microlepis. These are scenarios in which the selective filter does not allow variants with the highest fitness at a certain moment to prevail over their available alternatives. In similar cases, I will argue, citing fitness-enhancing effects does not represent an adequate explanation of what happens in the population, undermining the explanatory dimension of the selected effects theory. (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)

The subject of this thesis is physicalism, understood not as some particular doctrine pertaining narrowly to the philosophy of mind, but rather as a quite general metaphysical claim to the effect that everything is, or is fundamentally, physical. Thus physicalism explicates the thought that in some sense physics is the basic science. The aim of the thesis is to defend a particular brand of physicalism, which I call eliminative type physicalism. It claims, roughly, that every property is a physical property, (...) a property mentioned in the laws of physics, and hence that any putative property not identifiable with a physical property must be eliminated from our ontology. Eliminative type physicalism is apt to face three objections, and so my thesis, like Caesar's Gaul, falls into three parts. In the first, I argue against the idea that there are tenable positions, both physicalist and non-physicalist, alternative to eliminative type physicalism. I argue that each of these positions token physicalism (Fodor, middle Putnam), supervenience physicalism (Lewis, Horgan) and and a non-physicalist view I call pluralism (Goodman, late Putnam) is defective. In the second part, responding to the objection that there is just no reason to be a physicalist, I develop a positive argument for eliminative type physicalism, an argument resting upon a strong version of the explanatory test for reality according to which only explanatorily indispensable properties can justifiably be said to exist. In the third and final part, I argue, against the charge that eliminative type physicalism cannot accommodate what I call phenomenal properties (qualia, raw feels etc.), that there is no good reason to deny, and one good reason to affirm, that phenomenal properties just are physical properties. (shrink)

Abstract Surprisingly, little theoretical attention has so far been paid to the ?Comparative Assumption?: the attempt to extrapolate from species to species in psychology (and particularly to the human species). This paper examines the problems and the possibilities inherent in the Comparative Assumption. Perhaps the most important conclusion of the paper is that much more work is needed on this intriguing question.

The Scientific Revolution spawned not just one methodology, but two. We have emphasized Bacon's inductivism at the expense of Galileo's more abstract, sophisticated method of successive approximation, and so have failed to appreciate Galileo's contribution to the ceteris paribus problem in philosophy of science. My purpose here is to help redress this imbalance. I first briefly review the old unsolved problems, and then point out the Baconian basis of ceteris paribus, as this clause is conventionally understood, and its history from (...) Aristotle to twentieth century Positivism. Then I explore Galileo's method of dealing with unwanted impediments, and the more general problem of 'accidents.' I trace his methodology back to Archimedes and forward through the economic theories of Adam Smith (18th century), J. S. Mill (19th) and Milton Friedman (20th). Finally, I point out ways in which I think Galileo's scientific method sheds light on, and provides a partial solution to, the ceteris paribus problem. (shrink)