Space and time, Hegel maintains, are sometimes thought of as empty ‘containers’ (Behäl
ter) that exist prior to matter and are subsequently ‘filled’ by the introduction of matter, as it were, from the ‘outside’.61 For Hegel, by contrast, matter is not something distinct from space and time in this way, but is made necessary by space and time. This is because matter is precisely what space and time themselves, in their indissoluble unity, logically prove to be. Space and time, as we have seen, have shown themselves to be abstractions that have no existence by themselves but exist only in the form of motion. Hegel now demonstrates that motion is also an abstraction that turns out to be logically inseparable from matter.
For Hegel, therefore, there is never anything less than matter, and in this sense the great German ‘idealist’ can actually be considered a ‘materialist’. Note, however, that, unlike many other, self-proclaimed materialists, Hegel does not simply presuppose the existence of matter. He reaches the conclusion that matter is irreducible by demonstrating that pure,
‘immaterial’ space, time and motion undermine their own abstractness and ‘make them
selves into this reality which is matter’.62 In this way, Hegel proves that the presence of matter is not simply something contingendy given, but is a logical necessity.
Matter is made necessary by the distinctive logical structure o f motion. The latter, as we know, is the process whereby a place ceases being the particular place that it is and becomes another place, and then another and another, and so on. Motion is thus the process in which a place changes from being here to being there and then there. In this process of change, the place itself is not destroyed but endures: it simply relocates itself in space over time. As Winfield puts it, therefore, in motion ‘a determinate, reidentifiable space travels along the trajectory of motion’.63 This determinate space that retains its identity as it moves is what Hegel understands by matter, ‘since there is motion, something moves; but this something which persists is matter’. For Hegel, therefore, ‘there is no motion without matter’. Equally, ‘there is no matter without motion’, since matter is simply enduring, self
identical space that moves.64
Later in the philosophy of nature matter will turn out to have distinctive physical and chemical qualities: it will have density, cohesion, produce sounds, give off heat and be metallic, acidic or alkaline, and so on. The first thing that matter proves to be, however - and thus the very least that matter can be - is reidentifiable space in motion. In Hegel’s view, the science of mechanics is distinguished from that of physics proper by the fact that it seeks to understand only the various kinds of motion (and the specific relations between space and time they involve) that are characteristic of matter in general, regardless of its physical or chemical composition. As we shall see, mechanics, in Hegel’s view, also seeks to account for such motion without invoking the concept o f‘force’ and so coincides with kine
matics.65 From a mechanical or kinematical point of view, therefore, matter and motion are actually the same thing, understood once as a settled unity and once as process. This explains why an object can produce the same effect in another object through an increase in its mass (or weight) or in its velocity.66
By virtue of the fact that it endures through the course of its motion, matter retains a distinct identity of its own. It remains one and the same ‘self-relating’ space as it relocates itself from one place to another. By preserving its identity in this way, Hegel argues, matter necessarily excludes from the space it occupies any other self-identical moving space that it encounters. At its simplest, therefore, ‘matter is place that is exclusive’ To put this another way, matter necessarily repels any other matter that endeavours to move into its space. This is true of every material body and of every part of every material body. Each one resists the encroachment on its own spaqp by other bodies or parts of matter. Consequently,
‘matter is impenetrable [undurchdringlich] . . . ; where one matter is, there can be no other’.67 Impenetrability is thus not a contingent quality of matter, but is made necessary by the fact that matter preserves its identity as it moves.
As impenetrable, matter constitutes what Hegel calls ‘the first real limit in space’68 Geometrical lines and planes also bound space, but they constitute ideal rather than real barriers. Matter, by contrast, definitively bars the progress of other matter through the space it occupies. By virtue of doing so, it filk space in a way that geometrical figures alone do not. Since space has proven to be nothing less than matter, it would thus appear at this point that there is nothing in nature but filled space; and Hegel does, indeed, maintain that
‘there is no empty space’. It becomes clear later, however, that, even if space necessarily
proves to be filled space or matter, matter itself differentiates itself into independent celes
tial bodies - planets, moons and their sun - that are separated by empty space. Matter itself will thus make some empty space necessary.69
Hegel goes on to argue that matter consists not only in the mutual repulsion, but also in the mutual attraction, of its parts. Through its activity of repulsion, matter distinguishes itself into many distinct parts or units. All remain, however, units of one and the same matter. Despite its differentiation into manifold material bodies (and parts of bodies), therefore, matter actually forms a single, continuous unity and identity. All units of matter give expression to their essential unity through their mutual attraction for one another:
‘there is One which posits itself as many, and those that are distinguished . . . are one and the same; this is the determination of attraction which thus lies immediately in repulsion’.
Matter, for Hegel, is thus both the repelling of one unit of itself from another and the ‘posit
ing of the many as one’ in attraction.70
Indeed, matter cannot be one without the other: for repulsion, as the holding apart of what is essentially one and the same, must entail the mutual attraction of what is held apart, and attraction, as the unifying of what holds itself apart, must entail the mutual repulsion of the units that draw together. Matter, in other words, is both one and many at the same time, and so is the concrete embodiment of unity-in-difference.
Note that, in contrast to Kant, Hegel does not regard repulsion and attraction as forces within matter causing it to move in certain ways.71 He considers them to be the processes or movements in which matter consists. No forces are needed to explain such motion, because matter itself proves logically to be the very movement of repelling and drawing together with other matter. According to Hegel, this unity of attraction and repulsion that matter proves to be is gravity (Schwere).
In his Principia Newton understands gravity to be a centripetal force by which bodies are drawn or ‘impelled’ toward some point as their ‘centre’. For bodies on the earth this centre is located in the centre of the earth itself and for the planets it is in the centre of the sun.72 Since centripetal forces draw or pull bodies down or in toward such a centre, they are con
sidered by Newton to be ‘attractions’.73 Gravity, unlike magnetism, is the force of attraction that is found to be operative in all bodies and so is universal. Despite this, however, gravity, for Newton, is n o t‘essential to bodies’: it is not a property without which matter could not be conceived to be what it is.74 Gravity must, therefore, have a cause that is distinct from the simple nature of matter itself. Yet Newton maintains that the cause of gravity remains unknown and that he will not frame ‘hypotheses’ about its possible character.75
Hegel’s conception of gravity differs in significant respects from that of Newton. First, gravity (which is simply the unity of attraction and repulsion) is not a force within matter, in Hegel’s view. It is nothing but the motion towards other matter (or the propensity so to move) that is characteristic of all matter. As Hegel puts it, matter ‘is heavy [schwer], and the appearance of gravity is m otion’.76
Second, gravity is not a contingent property of matter without which matter would remain what it is. Gravity is, rather, the very essence or ‘substance’ of matter itself.77 It is the movement of uniting-with-other-matter that is intrinsic to matter as such (as opposed to magnetism which is the property of only certain kinds of matter). The statement that
‘matter is heavy’ is thus for Hegel - though not for Newton or, famously, for Kant - an analytic or ‘identical’ proposition.78 Accordingly, gravity is not merely an unexplained force in nature. It is a phenomenon whose occurrence is explained by the logical development of space and time that makes matter itself necessary.
Third, since gravity is matter’s own movement towards other matter, it cannot be a force that acts upon bodies from the outside and pulls them towards their centre.79 One needs
to exercise caution, therefore, when considering Heger$ claim that gravity is the unity of repulsion and attraction, because (unlike Newton) he does not understand gravity to be a force by which matter is passively attracted. True, he allows us to say (with Newton) that
‘matter is attracted by the centre’; but he makes it abundantly clear at several points that gravity is actually matter’s own, active ‘seeking’ or ‘striving’ to unite with other matter.80 Interestingly, Newton also talks at times (like Hegel) o f‘bodies seeking a center’81 He makes it clear at numerous points, however, that gravity is in fact an external force by which bodies are drawn or ‘impelled’ towards a centre.
Fourth, even if we understand ‘attraction’ as the active seeking of other matter, Hegel still insists that ‘it is essential to distinguish gravity from mere attraction’, because gravity is in feet the union of attraction and repulsion.82 It is the movement in which matter seeks to unite with other matter that it simultaneously repels and excludes from the space it occupies. This mom ent of repulsion is an ineliminable feature of gravitating matter and, indeed, constitutes its distinctive impenetrability. Accordingly, it prevents matter from ever achieving its goal of complete unity with other matter. Newton, of course, also recognizes that matter is both attracted to other matter and impenetrable. For Hegel, however, the repulsion of matter is a constitutive moment of gravitational attraction itself.
Perfect unity would only be attained, in Hegel’s view, if different parts of matter were able to overcome their own impenetrability and their separation from one another and occupy the same space. This, he maintains, would involve them collapsing into one point
‘if matter attained what it seeks in gravity, it would melt into a single point5. It is im
possible for matter to collapse into such a pure singularity, however, because ‘repulsion, no less than attraction, is an essential moment of matter’ and this necessarily keeps all parts of matter apart from one another, even if in some cases only to a minimal degree. Accord
ingly, matter forever seeks an intimate unity with other matter that it can never achieve:
‘the unity of gravity is [thus] only an Ought [Sollen], a longing, the most unhappy striv
ing to which matter is eternally condemned’.83
The point in space at which matter seeks its impossibly intimate unity with other matter is called by Hegel (following Newton) a ‘centre’ (Mittelpunkt). Since this centre lies absolutely beyond the reach of the matter that seeks it, it must not only be located outside such matter but also be a point that in principle cannot be occupied by matter at all. It must, therefore, be a wholly immaterial, unextended, ‘ideal singularity’: a purely geomet
rical point.84 This ideal centre will itself, however, be located within another material body.
When a terrestrial body fells, therefore, it seeks its ‘centre’ or point of unity not in the empty space on the other side of the earth but within the earth itself.85 Since gravity is thus matter’s movement - or propensity to move - towards an immaterial, geometrical ‘centre’ within another material body, it is, in Hegel’s view, the ‘confession’ by m atter of its essentially contradictory nature.86