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)

In the seventeenth century, Newton published his famous experimentum crucis, in which he claimed that light is heterogeneous and is composed of rays with different refrangibilities. Experiments, especially the crucial experiment, were important for justifying Newton’s theory of light, and eventually his theory of color. A century later, Goethe conducted a series of experiments on the nature of color, especially in contradistinction to Newton, and he defended his research with a methodological principle formulated in “Der Versuch als Vermittler.” Goethe’s principle (...) included two elements: a series of experiments and resultant higher empirical evidence, which functioned as mediator between the objective and the subjective . Although the notion of experimentum crucis became popular among scientists for reconstructing experimental research and for justifying theories, especially for rhetorical purposes, Newton’s justification of his theory of light and color is best reconstructed in terms of Goethe’s methodological principle. Finally, Goethe’s principle has important consequences for the contemporary philosophical underdetermination 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)

Johann Wolfgang von Goethe was well acquainted with Isaac Newton's work on refraction and his theory of light and colours. Indeed, he had painstakingly repeated those experiments in Newton's Opticks , which clearly demonstrate that light is heterogeneous. Yet Goethe never abandoned his belief that light is immutable and that colours result from the interaction of light and darkness. It is argued here that the origin of Goethe's refusal to accept Newton's theory was not psychological, as is commonly supposed, but (...) theological. It stemmed from his pantheistic belief in the spiritual nature of light, which he believed rendered it unknowable and not open to analysis. (shrink)