Climate policy decisions are decisions under uncertainty and are, therefore, based on a range of future climate scenarios, describing possible consequences of alternative policies. Accordingly, the methodology for setting up such a scenario range becomes pivotal in climate policy advice. The preferred methodology of the Intergovernmental Panel on Climate Change will be characterised as ,,modal verificationism"; it suffers from severe shortcomings which disqualify it for scientific policy advice. Modal falsificationism, as a more sound alternative, would radically alter the way the (...) climate scenario range is set up. Climate science's inability to find robust upper bounds for future temperature rise in line with modal falsificationism does not disprove that methodology, rather, this very fact prescribes even more drastic efforts to curb CO2 emissions than currently proposed. (shrink)

Positivism and, especially, Max Weber's vision of the modern disen chantment of the world are incoherent because they separate human culture from the environment in which human agents pursue their life- projects. The same problem is manifested, more blatantly, in current social studies of science, which take the project of disenchantment further by disenchanting science itself. A different image of science is traced to classical empiricism, whose paradigm of learning is belief and, more specifically, the practical nature of the believer's (...) experience of the environment of his or her actions. The believer's ecological imagery of the world, as it was elaborated by classical empiricism, provides the means to transcend the disenchanted image of the world and its prob lems. (shrink)

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)

In a 2004 paper, “Hume’s Missing Shade of Blue Reconsidered from a Newtonian Perspective,” Eric Schliesser argues that Hume’s well-known discussion of the missing shade of blue “reveals considerable ignorance of Newton’s achievement in optics,” and that Hume has failed to assimilate the lessons taught by Newton’s optical experiments. I argue in this paper, contrary to Schliesser, that Hume’s views on color are logically and evidentially independent of Newton’s results. In developing my reading, I will argue that Schliesser accepts an (...) overly broad interpretation of the implications of Newton’s experimental results, and takes inadequate account of Hume’s disciplined methodological restrictions on the kinds of experiential evidence that are to be admitted in building the foundations of his science of human nature. (shrink)

In this historical essay an attempt is made to discuss the problem of decisive experiments both from the point of view of History of Science and of Philosophy of Science. The first part deals with Francis Bacon's idea of instantiae crucis and with the use of the term experimentum crucis mainly in optics. With respect to the experimental confirmation of Maxwell's electrodynamics the Duhem‐Quine Thesis is discussed. Duhem had argued that not a single hypothesis but only a complete theory is (...) examined by experiment. So a single experiment neither can prove nor can disprove a single hypothesis. With regard to Bucherer's and Neumann's data concerning the velocity‐dependence of the electron's mass the question of the certainty of conclusions arising from experimental tests is treated. In the last parts the really historical problem of the decisive experiments is considered, namely the gap between the context of design of an experiment and the context of evaluation of an experiment in retrospect. The examples here are the Michelson‐Morley experiment, the Franck‐Hertz experiment, and the Compton‐Effect. In the conclusion parity violation is discussed. Perhaps due to the possibility of a single alternative in theory and an unambiguous result of the experiment this test really was crucial. In general, however, the experimentum crucis will prove to be a very seldom event. (shrink)

While Newton tried to make his telescope into a proof of the supremacy of his theory of colours over older theories, his instrument was welcomed as a way to shorten telescopes, not as a way to solve the problem of chromatic aberration. This paper argues that the image published together with the report on Newton’s telescope in Philosophical Transactions (1672) encouraged this reception. The differences between this visualization and other images of Newton’s telescope, especially that published in Opticks (1704), are (...) discussed. This paper shows that the image in Opticks adopted characteristics of a Cartesian program of visualization of machines and instruments which complemented a rhetoric which attributed primacy to theory over practice. The differences between the images in Philosophical Transactions and Opticks are also considered within the broader institutional context of Newton’s attitude towards the Royal Society. (shrink)