Abstract

Many familiar modal claims are clearly made against some set of background assumptions, as when making such claims, we hold fixed certain background truths, and intend to call attention to the fact that the ‘necessity’ in question is an invariable consequence of those truths. Ordinary explanations of particular phenomena that draw upon scientific theories are replete with modal concepts. Necessity plays a yet deeper role in the practice of formulating scientific theories. Alongside the ever increasing constraints of accumulating empirical evidence, theories are always held to the constraint of logical and mathematical consistency. This chapter expresses common philosophical claims concerning the place of modality in scientific explanations that have nonetheless been heavily challenged, especially in the twentieth century. It also considers and criticizes a range of views that stand opposed to robust modal realism.