Olaf Müller’s book develops a new case for underdetermination, and, as he is focusing on theories of a ‘limited domain’, this assumes the containability of the theories. First, the paper argues that Müller’s theory of darkness is fundamentally Newtonian, but for Newton’s optical theory the type of theoretical structure Müller adopts is problematic. Second, the paper discusses seventeenth-century challenges to Newton, changes in the proof-structure of Newton’s optical theory, and how these affect Müller’s reconstruction. Müller’s book provides empirically equivalent theories, (...) yet the historical theories were not empirically equivalent, and the same experiments were used to extract different bodies of evidence to rebut the opponent. Third, Goethe’s multi-layered critique of Newton’s experimental proof is investigated, including his developmental account of prismatic colours, the role of experimental series in rejecting Newton’s observations, and his incorporation of the ‘limited domain’ of prismatic colours in a broader framework. Two key elements of Goethe’s method, polarity and strengthening are discussed in contrast to Müller, who only utilises polarity in his account. Finally Neurath’s attempts to come to grips with the optical controversies and the prism-experiments with ‘blurred edges’ are recalled. Müller also discusses in detail some of these experiments and heavily draws on Quine. Neurath developed Duhem’s and Poincaré’s conventionalist insights and had good reasons to be pessimistic about theory-containment. Their differences provide some additions to the history of the Duhem–Quine thesis. (shrink)

The polarity of light and dark in the treatment of the Newtonian spectrum and the inverse spectrum is studied further and the validity of heterogeneity of light and darkness in relation to Goethe’s views is examined. In order to clarify the reality of the “darkness rays”, theexperimentum crucisis re-evaluated. It is shown that the commonly accepted analysis contains assumptions in the choice of the spectrum and background, which mask the inherent dynamic of the spectrum. The relation between colour and wavelength (...) is re-examined with respect to the immutability and specific refrangibility of colour. It is then shown that both these properties are approximations that apply under the specific conditions that have later become standardized in spectroscopy, leading to a consensus regarding the relation of wavelength to colours of one particular spectrum. This consensus has resulted in the study of colour diverging into spectroscopy and colour physiology. As an alternative, the basis of the dichotomy postulated by Müller is studied, leading to the realization that the resolution of this dichotomy was begun by Goethe with the idea of turbidity. A further study shows that turbidity resolves the apparent incompatibility of light and dark. (shrink)

Did Goethe devise an empirically viable theory of classical ray optics? Or can we at least make use of his ideas to propose one? And if so, does this confront us with an intriguing case of theory underdetermination? In this paper, which is mainly a comment on the recent work of Olaf Müller, I shall address these three questions and argue for ‘no, yes, no’. This is in contrast to Müller, who has recently launched a vivid defense of Goethe-style ray (...) optics :569–573, 2015b; Z Philos Forsch 69:588–598, 2015c; Br J Hist Philos 24:322–346, 2016). Müller aims to give an almost positive answer to all three questions: ‘perhaps, yes, yes’. My overall line of argument will be that the rather restricted regime of classical geometrical optics of spectral colors allows at best for a weak form of transient theory underdetermination that, in turn and more straightforwardly, also allows for a structuralist reading in terms of two structurally equivalent formulations of one and the same theory. However, extending any of the rivaling models of ray optics other than Newton’s beyond the mentioned regime and embedding them into physics in total—especially in view of thermodynamics—leads to a contradiction. Hence, Newton’s theory is confirmed as the only consistent theoretical interpretation of ray optics. (shrink)