6 - Epilogue: Optics as a mirror of eighteenth-century science

Summary

In his survey of historical literature on ‘experimental natural philosophy’ in the eighteenth century, J. L. Heilbron rejects attempts to make the rise of ‘Newtonianism’ and its ultimate triumph over ‘Cartesianism’ the guiding historiographical principle. The results reached in the present study on physical optics parallel Heilbron's argument. We have observed that, in the first half of the eighteenth century, the influence of the opposition between ‘Newtonianism’ and ‘Cartesianism’ in the discussion on the nature of light, also perceptible, was certainly not a dominant feature. Furthermore, there is confirmation for Heilbron's remark that the disciplinary borders of eighteenth-century experimental natural philosophy, especially optics, were subject to change and that it is precisely these changes that can provide us with a new historiographical guideline.

If we pursue the latter suggestion further, we meet with a general thesis advanced by T. S. Kuhn in 1975. Among all the available alternatives, this thesis is to my eyes the most suited to making the various developments in the eighteenth century comprehensible and to collecting them within one general viewpoint. However, when I attempted to use Kuhn's point of view for the clarification of eighteenth-century optics, I found that I could not use it as it stood. In this epilogue I shall propose a corrective to Kuhn's ideas, one that will be illustrated by material derived from the previous chapters. Before doing so, I shall present Kuhn's thesis itself, and examine the way in which he and others using it have described the development of optics.