The Leibniz–Clarke Correspondence
Absolute vs relational space and time
Venue: Private correspondence routed via Princess Caroline of Ansbach; published 1717 after Leibniz's death.
The deepest pre-Einstein debate over whether space and time are real things or relations among bodies.
Over five exchanges in 1715–1716, Leibniz wrote to Samuel Clarke (a theologian and protégé of Newton) attacking the Newtonian conception of space and time as absolute, infinite, eternal divine "sensoria." Clarke replied — almost certainly with Newton looking over his shoulder — defending substantival space-time, the void, and the contingent dependence of natural law on God's will. Leibniz pressed the principle of sufficient reason and the identity of indiscernibles; Clarke responded with appeals to the empirical reality of inertial effects (Newton's bucket) and to divine voluntarism. Leibniz died mid-correspondence; the exchange is the founding document of the substantival/relational dispute over spacetime, a dispute the eventual reception of general relativity arguably settled in neither side's favour.
Historical Context
Newton and Leibniz had earlier feuded over priority for the calculus (a separate dispute settled, mostly, in Newton's favour by the Royal Society). The Leibniz–Clarke correspondence is the larger and more durable confrontation between their broader natural philosophies.
Parties
Space and time are nothing over and above the order of co-existence and succession of bodies and events. Absolute space, time, and motion are unintelligible posits.
Key arguments
- Principle of sufficient reason: God would have no reason to place the universe in one absolute spatial location rather than another shifted by 5 metres — hence absolute space is empty.
- Identity of indiscernibles: bodies in spatially indiscernible situations would be the same body — hence pure spatial points cannot individuate.
- Plenum thesis: the world is fully filled; "void" is empirically and metaphysically empty.
- God as cosmic clockmaker requires no interventionist re-winding (against Newtonian providential clock-resetting).
Allied schools
Space and time are real, absolute, and infinite — in some readings, divine attributes ("God's sensorium"). Inertial effects require a substantival frame.
Key arguments
- Newton's bucket: rotation is empirically detectable from inside the bucket, requiring absolute space.
- PSR is satisfied by God's free choice (divine voluntarism), not by the absence of intrinsic spatial distinctions.
- Vacuum is empirically required by mechanics; the plenum is inconsistent with observed motion.
- The world is contingent and providentially maintained, not a self-running clock.
Dimensions Engaged
Space
The foundational debate over Space · Ontological Status: substantival vs relational, with the empirical question of inertia anchoring the substantivalist case.
Time
Time · Ontological Status: parallel substantival/relational question for time, with the further issue of whether time is divine (Newton).
Matter
Bears on Matter · Locality through the plenum/vacuum dispute.
Verdict in retrospect
Neither side is straightforwardly vindicated by general relativity. The dynamical metric of spacetime is real (against pure Leibnizian relationalism) but is no absolute frame (against Newtonian substantivalism). Modern structural readings (Earman, Maudlin) place spacetime structure between substance and pure relation, partially honouring both correspondents.
Related Debates
Sharing parties or aligned schools.
Related Experiments
Experiments that share dimensions and/or aligned schools with this debate.
Other Personas Aligned With This Debate
Ranked by declared-influence weight in the schools either party is allied with. The named parties themselves are excluded — they're already listed above.
Works Most Aligned With This Debate
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Related Films
Films engaging the same dimensions as this debate.
Related Contemporary Dilemmas
Dilemmas that engage the same dimensions as this debate.
Further reading
- Alexander (ed.), *The Leibniz-Clarke Correspondence* (1956)
- Earman, *World Enough and Space-Time* (1989)
- Vailati, *Leibniz and Clarke* (1997)