 Accordingly, the modern history of the philosophical investigation into thought experiments can be divided into four stages: in the 18th and 19th century the awareness of the importance of thought experiments in philosophy and science emerges. In addition to Lichtenberg, special mention should be made of Novalis (see Daiber 2001; Fehige 2013a), and Hans-Christian Ørsted. The topic reemerges in a more systematic manner at the beginning of the 20th century with little relation to the attempts made at the first stage. The stakeholders of the second stage were Pierre Duhem, Mach, and Alexius Meinong (see Duhem 1913, pp. 304–311; Mach, 1883, pp. 48–58, 1897 and 1905; Meinong 1907). A third stage, probably due to the rediscovery of the importance of scientific practice for a proper understanding of science, followed in the first part of the second half of the 20th century. Again, the contributions of this stage bear little relation to the two previous stages. While the third period has seen a number of noteworthy contributions (Cole 1983; Dancy 1985; Dennett 1985; Fodor 1964; Helm; Gilbert 1985; Helm et al. 1985; Krimsky 1973; McMullin 1985; Myers 1986; Poser 1984; Prudovsky 1989; Rehder 1980a,b; Yourgrau 1962 and 1967), the protagonists of this period were Alexandre Koyré, Kuhn and Popper. The ongoing philosophical exploration of thought experiments began in the 1980s, and marks the fourth stage. Arguably, it has been the most prolific one of all four stages. With some very important sign-postings in place (Horowitz and Massey (eds.) 1991; Sorensen 1992a, b, c; Wilkes 1988) the ongoing discussion took off in light of a debate between James Robert Brown and John D. Norton (see for a concise statement of each position Brown 2004; Norton 2004), which many have found useful to establish a contrast with their own alternative accounts of thought experiments. These views “represent the extremes of platonic rationalism and classic empiricism, respectively” (Moue et al. 2006, p. 69). They will be described below.