Abstract

Chapter 1 serves as an introduction to the vast topic of laws of nature. Thus, it first outlines the alleged characteristics of the laws of nature, namely truth, objectivity, contingency, necessity, universality, grounding counterfactuals and their role in science. Among these aspects, the peculiar modal status of laws of nature will be identified as the ‘holy grail’ of the debate. The second part of this chapter is concerned with the three main families of theories of laws of nature – neo-humean, ADT and dispositional theories – which are introduced and evaluated in regard to the aforementioned characteristics. It will then be argued that among those theories, the dispositional ones show the greatest promise of being able to account for the natural necessity of the laws of nature. Before a dispositional account of laws of nature can be given, dispositions themselves need to be understood. Consequently, Chapter 2 introduces various analyses of dispositions. As dispositions are pre-theoretically close to conditionals, a lot of analyses try to reduce dispositions to conditionals. This chapter critically assesses some chosen accounts: the simple conditional analysis, Carnap’s reduction sentences, the simple counterfactual conditional analysis, Lewis’ reformed conditional analysis, Malzkorn’s sophisticated con- ditional analysis, Choi and Gundersen’s context-dependent analysis, Manley and Wasserman’s gradable dispostion ascriptions, and Fara’s habituals. The prevention problem, which poses a threat to any account of dispositions, is depicted. It is argued that, ultimately, none of the conditionalising attempts is able to convince since they all exclude the problem cases which leads to explanation gaps and outlaw areas. Chapter 3 contains the synchronic part of my preferred solution to the prevention problem. The notion of ‘component causes’ is introduced, and the ontological status of components discussed. Millikan’s oil drop experiment is depicted en detail. In a first step, making a distinction between dispositions and the resulting behaviour is advocated. Via the symmetry argument, mani- festations and masks are shown to be ontologically on a par. In a second step, a triadic account consisting of dispositions, wirkungen and resultant behaviour, is established. Finally, the ontological interpretation of the trias is given. It is in the nature of the dispositions to bring about the wirkungen. These interact via combinations rules like the functions f and fa or vector addition, which are built-in into to dispositions. The diachronic part of my favourite interpretation, the triadic process picture of dispositions (TPD), is presented in chapter 4. The dynamics of dispo- sition manifestation are discussed and it is argued that fiddling with the trigger works only up to a certain point. Diachronic masking cases turn out to be no- torious. An excursus to action theory shows that the ontology needs to include processes, as understanding disposition manifestations as processes solves the diachronic prevention problem. The (TPD) can account for all counterexamples by taking the stimulus as the beginning of the manifestation process. Chapter 5 applies the (TPD) to the debate about laws of nature. In order to judge its adequacy, the characteristics of laws of nature given in chapter 1 are consulted. As a first step, the criteria truth, objectivity, universality, grounding counterfactuals and their role in science are covered. It is sketched how the (TPD) can account for these. The second part of the chapter deals with the modal status of the laws of nature. The dispositional essentialist’s view that laws of nature are metaphysical necessary is depicted and then criticised. It is argued that metaphysical necessity is not the appropriate modal status of the laws of nature. Finally, the (TPD) account of the necessity of the laws of nature is presented: laws of nature are naturally necessary and metaphysically contingent.