  Though Leibniz speaks here of the kingdoms of power and wisdom, the two-tiered explanatory approach – the phenomena of the natural world explained through efficient causes and the actions of the mind explained through final causes – leads to the distinction between what he more commonly calls the kingdom of nature and the kingdom of grace. (See Monadology §87) Thus, on Leibniz's view, we can understand the world as if designed by God, the perfect engineer or architect, and we can also understand the world as if ordered and guided by God, the supreme monarch, who is concerned solely with the happiness of his subjects.