An expression used by Gottfried Leibniz (and Voltaire's parody of Leibniz, Dr. Pangloss) to describe
the actual world. Leibniz's reasoning is that if there were a better possible world that was not
actualized, then God would not be a perfect being. Since he rejected the consequent, he had to
affirm the antecedent. (Leibniz also had much more complicated arguments for his view.)