ABSTRACT
Regularity without covering laws: causality and the a priori
Lydia Patton
Carl Hempel argues that at least some causal laws require provisos that set the conditions under which the law holds (it holds "provided that x"). Ron Giere contends that the need for provisos undermines "regularity" theories of causality, usually defined as a theory according to which an event causes another in case the second event follows the first repeatedly, and there is a covering law according to which the first event causes the second. Giere argues that the need for provisos in regularity theories locates uncertainty in a scientific theory at the level of theory, instead of at the level of scientific practice, where it belongs. Nancy Cartwright also uses an attack on covering laws to argue against regularity theories. In Nature's Capacities, Cartwright claims that Kelvin's empiricist skepticism about Maxwell's theory of electromagnetism is superior to the "abstract mathematical theories" of regularists. However, although Kelvin's contemporary, Hermann von Helmholtz, was an empiricist about scientific practice, he supported Maxwell's theory, and that support contributed to scientific progress. I show that Helmholtz has a theory of causality based on regularity that does not depend on covering laws in Hempel's sense. I claim that regularity theories without covering laws have a useful, limited function that Cartwright and Giere do not consider. Finally, I show how the search for regularities without covering laws may justify a limited role for the a priori in the sciences.