(say, by studying them in isolation) we can predict the behaviour of the complex whole. Mass in Newtonian physics may provide an example of such a situation ...

In a now-classic paper, Nancy Cartwright argued that the Humean conception of causation as mere regular co-occurrence is too weak to make sense of our everyday and scientific practices. Specifically she claimed that in order to understand our reasoning about, and uses of, effective strategies, we need a metaphysically stronger notion of causation and causal laws than Humeanism allows. Cartwright’s arguments were formulated in the framework of probabilistic causation, and it is precisely in the domain of (objective) probabilities that I (...) am interested in defending a form of Humeanism. In this paper I will unpack some examples of effective strategies and discuss how well they fit the framework of causal laws and criteria such as CC from Cartwright’s and others’ works on probabilistic causality. As part of this discussion, I will also consider the concept or concepts of objective probability presupposed in these works. I will argue that Cartwright’s notion of a nomological machine, or a mechanism as defined by Stuart Glennan, is better suited for making sense of effective strategies, and therefore that a metaphysically primitive notion of causal law (or singular causation, or capacity, as Cartwright argues in (1989)) is not – here, at least – needed. These conclusions, as well as the concept of objective probabilities I defend, are largely in harmony with claims Cartwright defends in The Dappled World. My discussion aims, thus, to bring out into the open how far Cartwright’s current views are from a radically anti-Humean, causal-fundamentalist picture. (shrink)

In their recent book Every Thing Must Go Ladyman and Ross (Ladyman et al. 2007) claim: (1) Physics is analytically complete since it is the only science that cannot be left incomplete (cf. Ladyman et al. 2007, 283). (2) There might not be an ontologically fundamental level (cf. Ladyman et al. 2007, 178). (3) We should not admit anything into our ontology unless it has explanatory and predictive utility (cf. Ladyman et al. 2007, 179). In this discussion note I aim (...) to show that the ontological commitment in (3) implies that the completeness of no science can be achieved where no fundamental level exists. Therefore, if claim (1) requires a science to actually be complete in order to be considered as physics, (1), and if Ladyman and Ross’s “tentative metaphysical hypothesis […] that there is no fundamental level” (178) is true, (2), then there simply is no physics. Ladyman and Ross can, however, avoid this unwanted result if they merely require physics to ever strive for completeness rather than to already be complete. (shrink)