Commentary on the Philosophy of Nature, Chapter 12
The Newton Critique
Here we find the most notorious passage in the volume, in two parts: one part of the critique holds up, the other does not.
What holds up. Hegel objects to explaining planetary motion by means of two forces — a centripetal and a centrifugal force — that balance each other out. His objection: what appears here as two forces is a single motion that has been decomposed after the fact; the decomposition is a calculational procedure, not information about the matter itself. And he is right that the centrifugal force is not a force at all in an inertial frame — that is textbook knowledge today.
What it cannot be played off against. Hegel’s own alternative is weaker. The same distinction must be made regarding the theory of colors: Stekeler notes that Hegel does not defend Goethe against optics as such, but against a dogmatic reductionism — against the thesis that colors are nothing other than results of the refraction of white light.[1] The objection targets the “nothing other than,” not the measurement. This does not rescue Hegel’s theory of colors; it only clarifies what it is directed against. Neuser further notes that Hegel qualitatively shares exactly what constitutes Newton’s achievement: describing terrestrial mechanics and celestial mechanics with unified laws.
The real difference lies elsewhere, and it is more interesting: Hegel conceives the planetary system as a system whose unity is constituted in the reciprocal relations among its members. He objects to the presentation found in Newton and Lagrange, in which the system appears to be built up step by step — in Lagrange’s perturbation calculus, one adds, in thought, a further planet to the sun and the first planet already considered. This is a computational technique; Hegel reads it as a claim about the matter itself and objects to it.[2]
Whether this objection is justified depends on whether one takes a calculational method for a statement about the object. The dispute, then, is not one about physics, but about its interpretation — and in this form it remains unresolved. [KF]