Editing Gottfried Wilhelm Leibniz (section)

===Physics===
{{See also|Dynamism (metaphysics)|Conatus#In Leibniz}}
Leibniz contributed a fair amount to the statics and dynamics emerging around him, often disagreeing with [[Descartes]] and [[Isaac Newton|Newton]]. He devised a new theory of [[Motion (physics)|motion]] ([[Dynamics (mechanics)|dynamics]]) based on [[kinetic energy]] and [[potential energy]], which posited space as relative, whereas Newton was thoroughly convinced that space was absolute. An important example of Leibniz's mature physical thinking is his ''Specimen Dynamicum'' of 1695.<ref>Ariew and Garber 117, Loemker §46, W II.5. On Leibniz and physics, see the chapter by Garber in Jolley (1995) and Wilson (1989).</ref>

Until the discovery of subatomic particles and the [[quantum mechanics]] governing them, many of Leibniz's speculative ideas about aspects of nature not reducible to statics and dynamics made little sense. For instance, he anticipated [[Albert Einstein]] by arguing, against Newton, that [[space]], time and motion are relative, not absolute: "As for my own opinion, I have said more than once, that I hold space to be something merely relative, as time is, that I hold it to be an order of coexistences, as time is an order of successions."<ref name="See H. G pp. 25"/>

Leibniz held a [[Relational theory|relational notion]] of space and time, against Newton's substantivalist views.<ref>Futch, Michael. ''Leibniz's Metaphysics of Time and Space''. New York: Springer, 2008.</ref><ref>Ray, Christopher. ''Time, Space and Philosophy''. London: Routledge, 1991.</ref><ref>Rickles, Dean. ''Symmetry, Structure and Spacetime''. Oxford: Elsevier, 2008.</ref> According to Newton's substantivalism, space and time are entities in their own right, existing independently of things. Leibniz's relationalism, in contrast, describes [[space and time]] as systems of relations that exist between objects. The rise of [[general relativity]] and subsequent work in the [[history of physics]] has put Leibniz's stance in a more favorable light.

One of Leibniz's projects was to recast Newton's theory as a [[Mechanical explanations of gravitation|vortex theory]].<ref name="Arthur p. 56">Arthur 2014, p. 56.</ref> However, his project went beyond vortex theory, since at its heart there was an attempt to explain one of the most difficult problems in physics, that of the origin of the [[Cohesion (chemistry)|cohesion of matter]].<ref name="Arthur p. 56"/>

The [[principle of sufficient reason]] has been invoked in recent [[cosmology]], and his [[identity of indiscernibles]] in quantum mechanics, a field some even credit him with having anticipated in some sense. In addition to his theories about the nature of reality, Leibniz's contributions to the development of calculus have also had a major impact on physics.

====The ''vis viva''====
Leibniz's ''[[vis viva]]'' (Latin for "living force") is {{math|{{var|m}}{{var|v}}{{sup|2}}}}, twice the modern [[kinetic energy]]. He realized that the total energy would be conserved in certain mechanical systems, so he considered it an innate motive characteristic of matter.<ref>See Ariew and Garber 155–86, Loemker §§53–55, W II.6–7a</ref> Here too his thinking gave rise to another regrettable nationalistic dispute. His ''vis viva'' was seen as rivaling the [[conservation of momentum]] championed by Newton in England and by [[Descartes]] and Voltaire in France; hence [[academic]]s in those countries tended to neglect Leibniz's idea. Leibniz knew of the validity of conservation of momentum. In reality, both energy and [[momentum]] are conserved (in [[closed systems]]), so both approaches are valid.