Schaffer on laws of nature

In ‘Quiddistic Knowledge’ (Schaffer in Philos Stud 123:1–32, 2005), Jonathan Schaffer argued influentially against the view that the laws of nature are metaphysically necessary. In this reply I aim to show how a coherent and well-motivated form of necessitarianism can withstand his critique. Modal necessitarianism—the view that the actual laws are the laws of all possible worlds—can do justice to some intuitive motivations for necessitarianism, and it has the resources to respond to all of Schaffer’s objections. It also has certain advantages over contingentism in the domain of modal epistemology. I conclude that necessitarianism about laws remains a live option.     

Principles,laws, theories and the metaphysics of science

In this paper an outline of a metaphysical conception of modern science is presented in which a fundamental distinction is drawn between scientific principles, laws and theories. On this view, ontologicalprinciples, rather than e.g. empirical data, constitute the core of science. The most fundamental of these principles are three in number, being, more particularly (A) the principle of the uniformity of nature, (B) the principle of the perpetuity of substance, and (C) the principle of causality.These three principles set basic constraints on the methodology of both empirical and theoretical science. The uniformity principle is central to the empirical aspect of science, suggesting a methodology consisting in the attempt to discover empiricallaws, while the causality principle is central to the theoretical aspect of science, suggesting the postulation of scientifictheories capable of indicating the causal basis of the laws. And the perpetuity principle functions so as to form a bridge between the theories and the laws.By distinguishing between principles, laws and theories in this way, a dimension is added to the analysis of modern science which allows for a more realistic account of its nature.     

Synthesis of theories through parametrisation of laws

The paper presents an example of unified theory bearing interest from both a historical and systematic point of view. The example is chosen from evolutionary population genetics (neo-Darwinian synthetic theory). It exhibits various aspects of theoretical change in science that have been shown in Part I (Geiger, 1988) to be characteristic of syntheses of theories.     

The justification and selection of scientific theories

This paper is a critique of a project, outlined by Laudan et al. (1986) recently in this journal, for empirically testing philosophical models of change in science by comparing them against the historical record of actual scientific practice. While the basic idea of testing such models of change in the arena of science is itself an appealing one, serious questions can be raised about the suitability of seeking confirmation or disconfirmation for large numbers of specific theses drawn from a massive list of claims abstracted from the writings of a few philosophers of science. The present paper discusses what one might reasonably expect from a model of change in science and then compares some clusters of theses from Laudan et al. with developments in recent theoretical physics. The results suggest that such straightforward testing of theses may be largely inconclusive.The research reported in this paper was partially supported by NSF grants SES-8318884 and SES-8606472. A preliminary version of this paper was read at the Conference on Testing Theories of Scientific Change held at Virginia Polytechnic Institute and State University, Blacksburg, VA, October 20–22, 1986.     

Approximative truth of fact-statements,laws, and theories

Summary The paper is a sketch of a conception of approximative truth (or verisimilitude). The concepts of relative error, and degree of inadequacy are introduced. By means of them the concept of truth-content of quantitative facts-statements, laws and theories is defined. Laws and theories accepted in science have a high truth-content, i.e. they are approximately true.     

A new characterization of scientific theories

First, I discuss the older “theory-centered” and the more recent semantic conception of scientific theories. I argue that these two perspectives are nothing more than terminological variants of one another. I then offer a new theory-centered view of scientific theories. I argue that this new view captures the insights had by each of these earlier views, that it’s closer to how scientists think about their own theories, and that it better accommodates the phenomenon of inconsistent scientific theories.     

Unexpected a posteriori necessary laws of nature

In this paper I argue that it is not a priori that all the laws of nature are contingent. I assume that the fundamental laws are contingent and show that some non-trivial, a posteriori, non-basic laws may nonetheless be necessary in the sense of having no counterinstances in any possible world. I consider a law L_S (such as ‘salt dissolves in water’) that concerns a substance S. Kripke's arguments concerning constitution show that the existence of S requires that a certain deeper level law or variants thereof hold. At the same time, that law and its variants may each entail the truth of L_S. Thus the existence of S entails L_S. Consequently there is no world in which S exists and fails to obey L_S. I consider the conditions concerning the fundamental laws that would make this phenomenon ubiquitous. I conclude with some consequences for metaphysics.