Hegel’s philosophy of nature is much more limited in what it can tell us about the world than is sometimes believed. It can demonstrate that a particular phenomenon is made nec
essary logically by another, but it cannot by itself reconstruct the empirical natural history of any such phenomenon. Philosophy must, therefore, leave it to science to study the natural processes that actually give rise to phenomena such as planetary systems and life.
Hegel points out that philosophy is also limited in another respect, because the phe
nomena whose logical necessity it demonstrates are in every case beset by irreducible con
tingencies that the logic of nature alone cannot account for. The existence of such contingencies is itself made necessary by the fact that nature is not simply the embodiment of reason, but is reason as ‘the negative of itself’; that is, reason in the form o f ‘the unrea
son of externality5.
We noted earlier that nature is contradictory, for Hegel, because the utterly lifeless and barren externality of space itself proves to be rationally self-determining and to contain the logical seeds of time, motion and matter. What now needs to be recognized is that nature is in fact contradictory in a further sense: for it is the embodiment of reason that is at the same time not purely or fully rational but shot through with illogical contingencies.
The essential contradiction in nature is thus ‘that on the one hand there is the necessity of its forms which is generated by the Concept [Begriff], and their rational determination in the organic totality; while on the other hand, there is their indifferent contingency and inde
terminable irregularity?5 It is important to remember that such contingency is not just an accidental feature of nature but is itself made necessary by the fact that in nature reason manifests itself as the negation of itself, as reason that is not just reason alone. In nature, therefore, ‘contingency and determination from without has its right’ and must be acknow
ledged by philosophy.26
Contingencies in nature will not necessarily lack all explanation and may prove on further reflection to have definite, identifiable causes and so, from a scientific point of view, to be law-governed and necessary. They are deemed to be contingent by philosophy, however, because they are not made necessary by the inherent logic of nature?1 From the perspective of philosophy, therefore, contingencies in nature constitute certain givens that ultimately have no rational foundation. The logic of nature may well make it logically nec
essary that there be organic life, that such life take the form of animals as well as plants, and - perhaps - that such life take to the air. It cannot, however, explain why in Hegel’s day there were apparently over sixty species of parrot.28 This and a whole host of other contingencies can only be explained - if they can be explained at all - by empirical science.
They bear witness, therefore, to what Hegel calls the ‘impotence of nature’ (die Ohnmacht der Natur): nature’s inability to shape itself purely in accordance with the determinations of its own inherent logic and its consequent need to ‘leave their detailed specification to external determination’29
This does not mean that philosophy itself turns out to be utterly impotent in the face of nature’s boundless and bewildering diversity. It does mean, however, that philosophy must restrict itself to determining what is made logically necessary by the sheer external
ity of space and must not aspire to explain every detail in nature. Hegel insists that ‘this impotence of nature sets limits to philosophy5 and that ‘it is quite improper to expect the Concept to comprehend - or as it is said, construe or deduce - these contingent products of nature’.30 As Gerd Buchdahl points out, ‘Hegel’s philosophy of nature is [thus] an enter
prise that displays much more intellectual sanity than has often been attributed to it’31 It does not endeavour - in an act of monumental philosophical hubris - to deduce every aspect of nature from the ‘Idea’, but seeks to deduce only what the logic of nature demon
strably makes necessary. Hegel well understands that a great deal of what there is in nature remains beyond the understanding of philosophy, but he wishes to show that, amidst the vast array of contingencies it contains, nature is none the less to a degree rational:
Philosophy has to start from the Concept, and even if it does not assert much, we must be content with this. The Philosophy of Nature is in error when it wants to account for every phenomenon.
. . . But what is known through the Concept is clear by itself and stands firm; and philosophy need not feel any disquiet [ Unruhe] about this, even if all phenomena are not yet explained.. . . There is plenty that cannot be comprehended yet; this is something we must grant in the Philosophy of Nature.32 Hegel’s aim, therefore, is a modest one. Yet it may still not be modest enough for some of his critics: for, although he clearly has no ambitions to explain the ‘totality7 of the universe philosophically, he does aim to provide a definitive, absolute, a priori account of what follows from ‘the Idea in the form of externality7. Indeed, Hegel’s modesty would make no sense without this ambition: for it is only by determining what follows necessarily from the logic of nature that one can know what counts (from a philosophical perspective) as contingent. As Hegel remarks in his 1823 lectures, ‘the Concept is the judge that decides what is the True’.33
To conclude this section, I will briefly consider one of the most famous charges to be levelled at Hegel: namely that he attempted to prove by pure reason alone - in an act of egregious immodesty - that there can be at most seven planets and that no planet can be situated between Mars and Jupiter. This charge was made by Popper in The Open Society and Its Enemies and was repeated in Jacob Bronowski’s The Ascent o f Many a book based on a television series that was seen by millions in the 1970s. Since many people may have been misled by Popper and Bronowski into thinking that Hegel was considerably more arrogant and foolish than I have been prepared to admit, it is im portant to set the record straight.34
In his 1801 dissertation, On the Orbits of the Planets, Hegel did try to explain why there were (as he thought) only seven planets, but as Olivier Depr£ has convincingly argued, he is in that work not by any means as guilty of mindless ‘apriorism’ as has often been claimed.
Towards the end of the eighteenth century a group of scientists, guided by an arithmetical series of numbers known as the ‘Titius-Bode Law7, committed themselves to looking for a planet between the orbits of Mars and Jupiter. Hegel regarded this law as non-rational and inexact, and suggested that an alternative exponential series, inspired by Plato's Timaeusy would be much more rational and would account for the gap between Mars and Jupiter.
Although Hegel would probably have heard reports that a minor planet had, indeed, been discovered precisely where he thought there was and should be a gap, he would not have had any reason at the time he was writing to regard the existence of this minor planet as anything more than conjecture. His motivation for preferring the exponential series was thus not only that it was more rational, but also that it corresponded more closely to what he took to be the currently known empirical facts. Indeed, from Hegel’s point of view, it was actually the scientists looking for a planet between Mars and Jupiter on the basis of an arithmetical series alone who were guilty of uncritical apriorism. Moreover, as Depre points out, although Hegel was wrong not to take the reports of the discovery of the asteroid Ceres more seriously, he was actually right not to place uncritical trust in the Titius-Bode law, as the discovery in 1846 of Neptune, whose distance from the sun does not correspond precisely to that law, would later demonstrate.35
In his later lectures on the philosophy of nature, by which time he has accepted the exis
tence of asteroids between the orbits or Mars and Jupiter, Hegel no longer maintains that he can account fully for the distances of the planets from the sun. In his 1821 lectures he does consider a law that might govern those distances, but he concludes that ‘it fits only approximately7.36 In 1823 he is even more cautious. He admits th a t‘it is a necessary demand that we also know this law [governing the distances of the planets]7 but he states - perhaps
echoing Newton’s famous declaration, T do not feign hypotheses’ - that he will not Venture here to set up any hypotheses about [such a law]’37
It is apparent from these passages, therefore, that Hegel is very far from being ‘hypno
tized by his own inspiring jargon’ and does not set out ‘to deceive and bewitch others’ with his ‘mystery method’ of dialectical logic, as Popper alleges.38 On the contrary, Hegel shows himself in his philosophy of nature to be capable of treating scientific issues with consid
erable circumspection and sanity. It is unfortunate that Popper and Bronowski were not similarly circumspect in the judgements they passed on Hegel.