Phil 560: The Nineteenth Century Philosopher-Physicists

Winter term 2026

In this course we'll be studying the philosopher-physicists of the nineteenth century, considering their different attitudes to the use of models and their various realist or anti-realist approaches during this period. We begin with the dominance of Laplacian physics early in the century and its concomitant hope that many phenomena could be explained via realistic models of Newtonian forces acting between particles at short distances. Following the demise of this Laplacian program, we'll turn to Maxwell's use of analogical reasoning in the 1850s and 1860s, seeing how his theoretical work was based on elaborate mechanical models even while he emphasized that those models should not be taken literally. This will lead us to "the Maxwellians" -- a group of British scientists who worked to unpack Maxwell's theory of electromagnetism, employing a great multitude of models in the process (sometimes literally built out of wooden rods and elastic bands). Returning to the continent, we then turn to the sign theories or picture theories of Helmholtz, Hertz, and Boltzmann, noting how each of these figures had a distinctive approach to the question of what a physical theory could successfully represent. Finally, we conclude with a brief discussion of how this nineteenth century background set the stage for the development of analytical philosophy in the twentieth century, focusing in particular on Wittgenstein.

Wednesday 7th January. Introduction.

• Poincaré (1905), The Value of Science,  §VII — "The history of mathematical physics" [6 pages]

Wednesday 14th January. *No class*
     Optional reading (highly recommended!):  Heilbron (1982), "Fin-de-Siecle Physics" [18 pages]

Wednesday 21st January. Laplacian Physics.

• Fox (1974), "The rise and fall of Laplacian physics" [48 pages]

​     Supplementary:

• Fox (1997), “Short-range forces” [5 pages]

Wednesday 28th January. Maxwell's analogies.

• Hesse (1974), “Logic of Discovery in Maxwell’s Electromagnetic Theory” [24 pages]

     Supplementary:

• Maxwell (1855), “On Faraday’s Lines of Force”, in The Scientific Papers of James Clerk Maxwell, Volume 1, pp.155-229; just read up to p.159 [4 pages]
• Maxwell (1861-1862), “On Physical Lines of Force” (op. cit.  pp.451-513); just read pp.451-452 and look at the plate at the end of Part II, after p.488 [2 pages]
• Klein (1973), "Mechanical explanation at the end of the 19th century" §4 (pp.67-70) [3 pages]

     Optional:

• Maxwell (1865), "Dynamical Theory of the Electromagnetic Field" (op. cit. pp.526-597); just read Part I, up to p.536 [10 pages]

Wednesday 4th February. The Maxwellians. 

• Hunt (1991), The Maxwellians, §4 — “Ether Models and the Vortex Sponge” (pp.73-107) [34 pages]

Wednesday 11th February. Helmholtz's sign theory.

• Helmholtz (1878), “The Facts in Perception”, in Epistemological Writings, pp.115-145 [30 pages]

     Optional:

• Heidelberger (1993), “Force, Law, and Experiment: The Evolution of Helmholtz’s Philosophy of Science” [36 pages]

Wednesday 18th February. Hertz's picture theory.

• Hertz (1899), The Principles of Mechanics Presented in a New Form — Introduction [40 pages]

     Optional:

• Eisenthal (2018), "Mechanics without mechanisms" [20 pages]

Wednesday 25th February. Boltzmann's picture theory.

• Boltzmann (1902), "On the development of the methods of theoretical physics in recent times", in Theoretical Physics and Philosophical Problems, pp.77-100 [23 pages]
• de Regt (1999), “Ludwig Boltzmann's ‘Bildtheorie’ and Scientific Understanding” [19 pages]

     Optional:

• Boltzmann (1897), “Lectures on Mechanics” Part 1 (op. cit. pp.223-254) [32 pages]

Wednesday 4th March. A survey of the nineteenth century.

• Klein (1973), "Mechanical explanation at the end of the 19th century" [21 pages]​
• Heilbron (1982), "Fin-de-Siecle Physics" [18 pages]

Wednesday 11th March. The scientific influences on Wittgenstein.
TBD
     Optional:

• Eisenthal (2022), "Models and Multiplicities"