German mathematician, philosopher, scientist, and diplomat. Leibniz was one of the greatest polymaths of his age and is credited, alongside Sir Isaac Newton, with the discovery of calculus.

Leibniz introduced the principle known as the “law of continuity,” that suggests that all changes in nature occur gradually, without sudden jumps and large changes. In his New Essays on Human Understanding, Leibniz wrote, “Nature never makes leaps.” Charles Darwin applied this concept to argue that species develop from earlier species through gradual and minute changes. In On the Origin of Species Darwin wrote:

Why should not Nature have taken a leap from structure to structure? On the theory of natural selection, we can clearly understand why she should not; for natural selection can act only by taking advantage of slight successive variations; she can never take a leap, but must advance by the shortest and slowest steps.

Leibniz also articulated the “principle of plenitude,” as identified later by intellectual historian Arthur O. Lovejoy. The principle posits that the universe, created by a perfect God, contains the maximum possible diversity of created and existent things. Every conceivable form of being that can exist does exist, filling all possible niches in a continuous, hierarchical chain from the simplest matter to God. To Leibniz the actual world is the “best possible world,” with no gaps or unrealized possibilities. While Plato and others laid the conceptual groundwork for these ideas, Leibniz is credited by Lovejoy with defining and popularizing the principle of plenitude in a more modern philosophical form.

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