 Further reading: On Hempel’s theory of explanation see Hempel 1965 and Fetzer 2010 [2017]. On the notion of probabilistic causality and the relative debate see Hitchcock 1997 [2016] and Beebe, Hitchcock &amp; Menzies (eds.) 2009. Salmon’s view of a causal process and Dowe’s conserved quantities theory are discussed in Dowe 2000. The debate on explanation is surveyed in Woodward 2003 [2017].