Routledge History of Philosophy Volume IV

RENAISSANCE AND SEVENTEENTH-CENTURY RATIONALISM 369
SPACE AND TIME
As we have seen, Leibniz speaks of monads as having points of view, but this
expression is metaphorical; it must not be taken literally as implying that monads
occupy positions in space. This is clearly not Leibniz’s view. Unfortunately,
Leibniz never offers a detailed account of the relations between his doctrine of
monads and his theory of space, but he seems to hold that spatial relations are
logical constructions out of the perceptual states of monads. In other words, the
claim that a certain body is in such and such a spatial position is to be ultimately
analysed in terms of propositions about monads and their properties. Thus from
his knowledge of the perceptual states of monads, God could read off all the
facts about the spatial relations of bodies in the universe. Leibniz is committed, it
seems, to the same view of time mutatis mutandis. Strictly speaking, monads are
no more in time than they are in space, but the temporal relations of events can in
principle be read off from the properties of monads. How consistently or
rigorously Leibniz adhered to this view of time is unclear.
At the very end of his life the nature of space and time was the subject of a
fierce controversy between Leibniz and Newton’s disciple, Samuel Clarke; the
exchange thus took place at a point in Leibniz’s career when the doctrine of
monads was securely in position. Despite this, in the controversy with Clarke
Leibniz does not seek to reveal the idealist groundfloor of his metaphysics.
Throughout this exchange Leibniz argues at an intermediate level of
philosophical rigour; 58 for the sake of argument he assumes that the phenomenal
world of bodies in space is ontologically basic. We should also note that while the
nature of space and time is the dominant topic in the correspondence with Clarke,
it is by no means the only issue that divides Leibniz and Newton; Newton’s
theory of universal gravitation is also one of Leibniz’s chief targets. Indeed, in
his later years, Leibniz was engaged in a full-scale assault on the foundations of
Newtonian science. According to Leibniz, Newtonian science was not only
philosophically inept; it was a direct threat to natural religion. 59
In the correspondence with Clarke Leibniz puts forward two positive theories
about the nature of space and time. In the first place, Leibniz argues that space
and time are not substances or attributes but relations. ‘Space is the order of coexistences;
time is the order of successive existences.’ 60 Thus Leibniz directly
opposes the Newtonian absolute theory according to which space and time are
entities which exist independently of bodies and events. For Leibniz, by contrast,
bodies are logically prior to space and events are logically prior to time; in other
words, there would be no space if there were no bodies and there would be no
time if there were no events. 61 Second, Leibniz argues that space and time are
ideal. This thesis follows from the relational theory in conjunction with Leibniz’s
oft-repeated claim that substances alone are fully real, everything else being a
mere ens rationis or mental construct. The claim that space and time are ideal
might lead one to suppose that it is intimately tied in with the doctrines of the
monadology, but in fact it is not; although it is fully consistent with those doctrines,