Online research in philosophy

How are scientific explanations possible in ecology, given that there do not appear to be many—if any—ecological laws? To answer this question, I present and defend an account of scientific causal explanation in which ecological generalizations are explanatory if they are invariant rather than lawlike. An invariant generalization continues to hold or be valid under a special change—called an intervention—that changes the value of its variables. According to this account, causes are difference-makers that can be intervened upon to manipulate or control their effects. I apply the account to ecological generalizations to show that invariance under interventions as a criterion of explanatory relevance provides interesting interpretations for the explanatory status of many ecological generalizations. Thus, I argue that there could be causal explanations in ecology by generalizations that are not, in a strict sense, laws. I also address the issue of mechanistic explanations in ecology by arguing that invariance and modularity constitute such explanations.

I compare two competing positions regarding relations between sciences: reductionism and explanatory pluralism. I argue that reductionism is not warranted by evidence from scientific practice, but on the other hand, it is important to emphasize certain fundamental differences between generalizations and explanations of different levels. To show this, I take up Woodward’s notion of invariance, arguing that lower-level generalizations generally have a higher degree of invariance under interventions than higher-level generalizations. Since degree of invariance tracks degree of explanatory depth, lower-level explanations are in this sense better than higher-level ones.

This paper defends a counterfactual account of explanation, according to which successful explanation requires tracing patterns of counterfactual dependence of a special sort, involving what I call active counterfactuals. Explanations having this feature must appeal to generalizations that are invariant--stable under certain sorts of changes. These ideas are illustrated by examples drawn from physics and econometrics.

This article examines methodological individualism in terms of the theory that invariance under intervention is the signal feature of generalizations that serve as a basis for causal explanation. This theory supports the holist contention that macro-level generalizations can explain, but it also suggests a defense of methodological individualism on the grounds that greater range of invariance under intervention entails deeper explanation. Although this individualist position is not threatened by multiple-realizability, an argument for it based on rational choice theory is called into question by experimental results concerning preference reversals. Key Words: methodological individualism • mechanisms • explanation • invariance • preference reversal.

Many philosophers have believed that the laws of nature differ from the accidental truths in their invariance under counterfactual perturbations. Roughly speaking, the laws would still have held had q been the case, for any q that is consistent with the laws. (Trivially, no accident would still have held under every such counterfactual supposition.) The main problem with this slogan (even if it is true) is that it uses the laws themselves to delimit qs range. I present a means of distinguishing the laws (and their logical consequences) from the accidents, in terms of their range of invariance under counterfactual antecedents, that does not appeal to physical modalities (or any cognate notion) in delimiting the relevant range of counterfactual perturbations. I then argue that this approach explicates the sense in which the laws possess a kind of necessity.

In this article I consider the challenges for exporting causal knowledge raised by complex biological systems. In particular, James Woodward’s interventionist approach to causality identified three types of stability in causal explanation: invariance, modularity, and insensitivity. I consider an example of robust degeneracy in genetic regulatory networks and knockout experimental practice to pose methodological and conceptual questions for our understanding of causal explanation in biology. †To contact the author, please write to: Department of History and Philosophy of Science, University of Pittsburgh, 1017 Cathedral of Learning, Pittsburgh, PA 15260; e‐mail: smitchel@pitt.edu.

This paper describes an alternative to the common view that explanation in the special sciences involves subsumption under laws. According to this alternative, whether or not a generalization can be used to explain has to do with whether it is invariant rather than with whether it is lawful. A generalization is invariant if it is stable or robust in the sense that it would continue to hold under a relevant if it is stable or robust in the sense that it would continue to hold under a relevant class of changes. Unlike lawfulness, invariance comes in degrees and has other features that are well suited to capture the characteristics of explanatory generalizations in the special sciences. For example, a generalization can be invariant even if it has exceptions or holds only over a limited spatio-temporal interval. The notion of invariance can be used to resolve a number of dilemmas that arise in standard treatments of explanatory generalizations in the special sciences.

The issue of whether there are laws in biology and the “special science”1 has been of interest owing to the debate about whether scientific explanation requires laws. A well-warn argument goes thus: no laws in social science, no explanations, or at least no scientific explanations, at most explanation-sketches. The conclusion is not just a matter of labeling. If explanations are not scientific they are not epistemically or practically reliable. There are at least three well-known diagnoses of where this argument goes wrong. First, the argument that there are no laws in social science adopts an account of laws that is too stringent, one that not even the physical sciences satisfy (Cartwright 1983, Mitchell 2000). On a less stringent definition, there are plenty of laws in social science (and biology). These laws are, sensu Fodor, “non-strict,” as opposed to the “strict laws” (if any—vide Cartwright 1983) of physics. Second, scientific explanation does not require laws, and when laws do explain, they do so because they satisfy some other requirement on scientific explanation, for example unification, or the identification of causal difference-makers (Friedman 1974, Kitcher 1989, Salmon 1984, Strevens 2009). A third view, increasingly attractive among philosophers of social science and biology is due to James Woodward (2000, 2003). This view, like the second one eschews laws and identifies causes as difference makers. On this view explanations do require regularities, but these regularities need only satisfy a requirement of “invariance” under certain specified circumstances, in order to be explanatory, and..

Descriptions of social norms can be explanatory. The erotetic approach to explanation provides a useful framework. I describe one very broad kind of explanation-seeking why-question, a genus that is common to the special sciences, and argue that descriptions of norms can serve as an answer to such why-questions. I draw upon Woodward’s recent discussion of the explanatory role of generalizations with a significant degree of invariance. Descriptions of norms provide what is, in effect, a generalization regarding the kind of historically contingent system— a group or society, a generalization with a significant degree of invariance. Key Words: explanation • invariance • norms • social sciences • erotetic • laws.

I identify the special sort of stability (invariance, resilience, etc.) that distinguishes laws from accidental truths. Although an accident can have a certain invariance under counterfactual suppositions, there is no continuum between laws and accidents here; a law's invariance is different in kind, not in degree, from an accident's. (In particular, a law's range of invariance is not "broader"--at least in the most straightforward sense.) The stability distinctive of the laws is used to explicate what it would mean for there to be multiple grades (or degrees) of physical necessity. Whether there are is for science to discover.