The Duality of Time Theory

Leibniz’s vis viva (Latin for "living force") is, 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. 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 in France; hence academics in those countries tended to neglect Leibniz’s idea. In reality, both energy and momentum are conserved, so the two approaches are equally valid.