Among the features of Aristotelian thought that had to be overthrown in order for the new cosmology to emerge was Aristotle’s account of the nature of space, and it would be in the context of arguments over the new conception of space that Continental idealism would be born.
in the Aristotelian cosmos there was a differentiation between the sublunar and superlunar realms…… The sublunar, effectively terrestrial, realm was the realm of generation and decay, while the superlunar or celestial realm was one of constancy and perfection. In the former, motion was between fixed places and, effectively, linear; in the latter, the movement of more perfect bodies, such as that of the stars, was circular, as that is the only form of motion that can go on eternally in finite space. As the derivative term, space was just the totality of differentiated places.
Within the scientific cosmology that unfolded between Copernicus and Newton and that came to replace the ancient geocentric view, there were no differentiated “places” in Aristotle’s sense: space, as finally established by Newton, was “isotropic”. That is, “space”, rather than place, was conceived of as singular, infinite and uniform, and so with no inherent directions.
In the sixth century, Philiponus had argued in a very un-Aristotelian and seemingly “modern” way that space was “a certain interval, measurable in three dimensions, incorporeal in its very nature and different from the body contained in it”. Later, in the fifteenth century, the fundamentally egocentric nature of the Aristotelian conception was exposed and criticised by Nicholas of Cusa, who conceived of space as an “infinite sphere” whose centre is everywhere and circumference nowhere,2 suggesting that the very idea of a “centre” of the universe was a relativistic or perspectival one. The “centre” was just where the observer was located, and so Cusa claimed that regardless of where an observer were located throughout the universe, it would appear to that observer that they were at the “centre”.
But Giordano Bruno, inspired in part by Cusa, radicalised Copernicus’ move by infinitising the universe and depriving it of both a boundary and a centre, making available the modern infinite and homogeneous conception of space.
One reason for this followed from his concept of substance (ousia): How could there be a void, if a void is nothing rather than something? Space had to be something, so it had to be a plenum rather than a void.
“It is clear”, Aristotle puts it in On the Heavens, “that there is neither place nor void nor time beyond the heavens” (OH: 279a12).
However, Aristotelian cosmological space, according to Max Jammer, could not be geometrised: “How could Euclidean space, with its homogeneous and infinite lines and planes, possibly fit into the finite and anisotropic Aristotelian universe?” (Jammer 1954: 26). Thus, such a project of mathematising the world came to be rejected by Aristotle as well as by the atomists and the Stoics (Funkenstein 1986: 34), and it had to wait for Newton to carry it out systematically and coherently. However, Newton had to have available to him an adequately de-Aristotelianised conception of space to do this.
Like Aristotle, then, Descartes had argued against the notion of void space: all space must be occupied by something, just in the way that our ambient space, for example, is occupied by air.
It was this attribution of extension to spirits that had allowed him to think of void space in a new way, and, apparently taking the idea from cabbalistic writings,7 he conceived space itself as a spiritual substance, or as an attribute of a spiritual substance.
In short, space could be conceived as infinite and as singular because it was an attribute of God. This idea was important for Newton.8
In his mathematised physical theory, Newton was reliant on the distinction between relative and absolute motion.
At a physical level, he employed a thought experiment involving the rotation of water in a rotating bucket to try to argue the case for motion that could be considered absolute rather than relative to some arbitrarily chosen framework (MPNP: vol. 1, 6–12). At a metaphysical level, however, he needed a conception of space that would make sense of the idea of absolute space within which the question of any object’s motion or rest could be answered definitively. More’s Neoplatonic understanding of space, as an attribute of God, answered that need.
After Newton, the success of his physics seemed to provide a retrospective justification for the conception of absolute space as a type of infinite, empty container, at least until the late nineteenth century, when the issue of absolute space again came under attack in a development that eventually led to modern relativity theory. However, while this “empty container” view of space is commonly understood as “Newtonian”, it should be remembered that for Newton himself, space was not empty. Rather, for him just as for More, space was full—it was full of God.
And while Newtonian physics is now commonly taken as an exemplification of a naturalistic attitude to the world, if we look to Newton’s own conception of the science he was developing, it presupposed a metaphysics that could not be further opposed to naturalism—in the conception of absolute space at the core of the theory, it presupposed a form of metaphysical spiritualism.
This God is the most fundamental reality in the sense that the material world that exists in space depends on him as both its creator and as its ruler. First, as dependent on its creator, matter has no necessary existence, we can conceive of absolute space as empty, and it is within God’s power to have not created the material world, that is, to have not put matter into space. (In contrast, we cannot conceive of the absence of space itself.) Next, neither does matter have the autonomous power to act: it is an inert, “dead” stuff moved around by a force external to it. This force is the will of God. The laws according to which matter moves—the laws we know as Newton’s laws—are laws decreed by God, analogous to the laws decreed by a king. God can act on matter because he is present everywhere throughout the absolute space in which matter moves. And just as this ubiquity secures his omnipotent capacity to act, it secures his omniscient capacity to know what happens in at every point of the extended world.10
The difference between these theological views in fact went back to the first centuries of Christianity. Newton’s God as omnipotent creator and external lawgiver was effectively the God of St Augustine. The God of the Radicals was, like that of Böhme, closer to the “Platonic theology” of the pagan Neoplatonists Plotinus and Proclus, for whom the material world was an “emanation” from the divine “One”, rather than a creation of a God like that of Augustine.12
Newton’s conception of space was one of the issues on which his bitter dispute with Leibniz was to turn, a dispute ultimately played out in the exchange of letters between Leibniz and Newton’s follower, Samuel Clarke (L-C). Relations between Newton and Leibniz had become acrimonious over the issue as to which of them was the actual discoverer of the calculus, but larger issues than this separated the two men.
In fact, we might take the dispute between Newton/Clarke and Leibniz as emblematic of an emerging distinction between what would come to be known as anglophone and “Continental” styles of thought.
An examination of the differences between the Berkeleian and Leibnizian criticisms of Newtonian realism about space and time will thereby provide a way of grasping the significance of the post-Leibnizian tradition.
Leibniz was to reject Newton’s conception of absolute space, arguing for a conception of space as relational. That is, for Leibniz the very ideas of space and time were simply abstractions from relations of coexistence or succession between objects (or more accurately, between the representations making up the contents of particular “monads”).
In the exchange with Clarke, Leibniz criticised both Newton’s conception of space and the conception of God linked with it. Moreover, this opposition to Newton’s spatial realism would, with Kant, come to be linked to an opposition of the “spiritual realism” associated with Newton’s view of space. Following recent treatments of the development of Kant’s critical philosophy, I will argue that his move to transcendental idealism was in part triggered by his realisation that his own early philosophical position (in which he tried to combine elements of Newton and Leibniz) entailed the type of crude popular form of spiritualism found in More, with its connections to belief in occult phenomena. In Kant’s case, this position would be personified in the figure of Emmanuel Swedenborg (1688–1772) who, like More, was a believer in various types of “spiritual” occurrences.
Both Leibniz (and after him, Kant) and Berkeley were critical of Newton’s conception of space and time. But, as might be expected, while Leibniz’s objections were “rationalist” ones, Berkeley’s were of an “empiricist” nature, and this gave very different meanings to their respective anti-realist or “idealist” views about space.
Clarke’s objections to Leibniz are revealing in terms of Clarke’s implied theology. Behind his objections lies the stance of theological “voluntarism”, a stance that had become explicit in the thirteenth century, as a reaction to the influence of Aristotelianism as found in the views of Thomas Aquinas. As will be seen, the significance of voluntarism as a position the Continental idealists opposed is crucial for understanding this movement, and here they tapped into a long-standing anti-voluntarist tradition. In Germanspeaking regions of Europe especially, anti-voluntarist ideas were transmitted through late medieval figures like Albert the Great and Meister Eckhart,17 and it was the tradition from which the “oppositional” thoughts of Jakob Böhme had sprung. It was to be especially influential among the post-Kantian idealists, and so a short detour into the theological disputes of late medieval Christianity is therefore warranted.
Pierre Duhem claimed that the orthodox and voluntaristic insistence on God’s absolute power from the late thirteenth century had liberated European thought from the constraints of Aristotelianism and opened up the possibility of natural science (Duhem 1985).
The church’s insistence on God’s absolute power was in effect a move against that type of non-voluntarist versions of Christian Platonist thought in which ideas were conceived of as equally real as the divine mind that thought them and were not, as in Augustine, reducible to the subjective thoughts of God.
For Leibniz, God acts according to two basic principles, the law of non-contradiction and the law of sufficient reason: the former represents a type of metaphysical, and the latter, a type of moral necessity.
In short, in Leibniz’s opposition to Newton’s conception of space we find the implicit opposition of a Platonist to Newton’s voluntaristic theology.
Berkeley, in his Principles of Human Knowledge (of 1710), argued against the legitimacy of the inference to something outside the mind that corresponded to and was causally responsible for those ideas
Here Leibniz alludes to the central metaphysical claim of Principles—the claim that “matter is nothing”, Berkeley’s “immaterialism”. This is the doctrine often taken as definitive of idealism, despite the fact that Berkeley himself never describes his position as “idealist”. But Berkeley’s immaterialism is in fact a consequence of his underlying spiritual realism.
However, he interprets this in terms of their dependence on another will: “There is therefore some other will or spirit that produces them” (ibid.: §29). That is, he still requires the perceived properties to be supported by some substrate analogous to Locke’s “I know not what”, and this substrate is interpreted as a spiritual one, the mind of God.
Focusing on the nominalism of Berkeley’s position will allow us to get a clearer sense of what the Continental idealists were committed to, given their strong anti-nominalist stand, a stand relating to their anti-voluntarism. In brief, my argument will be that in the wake of Leibniz, Continental idealism was characterised by an anti-nominalist opposition to empiricism, and that in the wake of Kant, a critique of the metaphysical conception of spirit or mind as a type of nonmaterial substance.
For “nominalists”, like Ockham, “universals” (Platonic ideas) were only names. In the world itself, there were only particular objects— particular dogs, particular chairs, particular clouds, and so on—and above and beyond these, no separate kinds of objects, no “genus” dog, chair or cloud.
Berkeley says of God in the Three Dialogues, that he “perceives nothing by sense as we do; [his] will is absolute and independent, causing all things, and liable to be thwarted or resisted by nothing … God Knows, or hath ideas; but His ideas are not conveyed to Him by sense, as ours are” (TD: 86–87).