Commentary on the Philosophy of Nature, Chapter 2
Three Things to Keep Apart
The bad reputation does not strike a single work but three different things within it, and they age at different rates.
First, the method. Hegel investigates which determinations belong together and how they follow from one another. This is a question addressed to concepts, not to nature, and it can be assessed independently of whether the natural science of 1830 still stands.
Second, the state of science. Much of what Hegel uses to develop his determinations is outdated: the Empedoclean elements, caloric, the theory of comets. Some of it was already contested in his own time.
Third, the claims about particulars. The number of planets, the theory of colors, the position of the earth. Here Hegel is mistaken, and not merely because science moved on, but because he wanted to derive from a structure something that does not follow from it.
The three levels are connected, but they do not coincide. Whoever demonstrates the third error has not touched the first. [KF]