Gottfried Leibniz was not the first philosopher to think that we live in the best of all possible worlds. He may have been the unluckiest, suffering the posthumous fate of being skewered in the best of all possible parodies, Voltaire’s “Candide” (1759). When Voltaire was writing, four decades after Leibniz’s death, the German polymath was renowned for his work in several sciences, philosophy, history, law, and, especially, mathematics—he and Newton had, independently, invented calculus, but it’s Leibniz’s notation that’s still used today. Over the years, Leibniz’s reputation continued to grow as more unpublished work came to light, some of which would make him the godfather of the digital age. But he will never quite live down Voltaire’s ridicule.
Leibniz was too logical about God. Like some ancient Stoics, he reasoned that, if God is omnipotent and good, ours has to be the best of all possible worlds, because if a better world had been feasible God would have made that one instead. All our sufferings must therefore be lesser evils that somehow serve to bring about a greater good. This solves the age-old puzzle of why God lets bad things happen. “I cannot show you this in detail,” Leibniz conceded, because no finite mind can see all the connections between events. But God had surely done all the relevant sums. So, Leibniz insisted, we may rest assured that any imagined world that might seem happier than our own would actually have been worse over all.