Properties for and of Better Best Systems

Many advocates of the Better Best System Account (BBSA) and variations thereof suggest that Lewis-style best system competitions can successfully be executed for any arbitrary but fixed set of predicates/properties. This affords the possibility to launch system analyses separately for each of the special sciences. However, predicates/properties of these sciences are unlike the perfectly natural properties Lewis envisaged in that they are non-fundamental, maybe non-natural, and not intrinsic. Moreover, they might be dispositional, i.e. already equipped with a nomological profile. The latter fact conflicts with the idea that it is only via the BBSA that nomological facts emerge. Furthermore, the special sciences’ predicates might be vague or even without extension. All these are challenges pertaining to these predicates/properties in themselves. Further challenges arise for the BBSA when it comes to eligible sets of such properties/predicates: What are the boundaries between the different sets of properties that demarcate the sciences? Also, the BBSA is in danger of depicting the whole of science as a patchwork of unrelated, maybe even contradictory systems. Is there a unity or a hierarchy to be found after all? The latter issues concern the interrelations across separate best systems and their properties. Relating to scientific progress, there are internal issues as well: as a science develops, it hosts different sets of properties. System analyses for different property sets, however, might well be incommensurable. How can the BBSA account for this? This chapter aims to give answers to most of these challenges.