# Leibniz, physics and the best of all possible worlds

Liebniz as a scientific thinker is known as a codiscoverer of the Calculus, along with Newton; as a philosopher he is also known for his phrase 'best of all possible worlds', which was apparently an attempt by him to solve the theodical problem of evil, and a phrase parodied by Voltaire in Candide.

Is there any connection between this aspect of his philosophy and his philosophy of the physical world, or nature?

Consider, that Newtonian Mechanics in its Hamiltonian formulation posits the dynamics of a system as the 'best' trajectory in phase space; and there are corresponding perspectives in Relativity and field theory - classical and quantum; and this is genealogically related to the principle of shortest time by Hero of Alexandra, Ibn Haytham and Fermat.

• math.purdue.edu/~eremenko/bernoulli.html has some interesting comments on the history of the physics side of this.
– Dave
Commented Jun 25, 2015 at 16:33
• Classical trajectories are not exactly the "best", it was already known in 19th century that they do not necessarily represent maximum or minimum of action, only a stationary value. However, that was after Leibniz's time, and "the product of mass, velocity and distance is mathematically the equivalent of the integral of live force over time. Leibniz had already shown that this quantity is likely to be either minimised or maximised in natural phenomena". So likely yes. Commented Jun 25, 2015 at 17:50
• @dave: your link says, and paraphrasing: that the variational calculus in the 18C, for the reasons I listed above, was considered as a proof of God. This was what I was looking for - but unfortunately no reference. Thanks. Commented Jun 26, 2015 at 8:57
• @conifold: Where is your quote from? Which physical quantity is the product of mass, velocity and distance, i.e. of momentum and distance? How does it relate to the action from the variational principle of least action? Commented Jun 28, 2015 at 20:36
• @jo wehler The quote is from here en.wikipedia.org/wiki/… Commented Jul 3, 2015 at 0:32