The term 'in the best of all possible worlds' is a phrase coined by the German philosopher Gottfried Leibniz in 1710. It refers to the idea that, despite the imperfections of the world, it is still the best of all possible worlds because it is the most perfect world that God could have created. This phrase has been used in literature and philosophy to refer to the idea that, even though the world may not be perfect, it is still the best it can be.