Leibniz combines Aristotelian teleology in the notion that the nature of a thing provides for its unfolding in a certain fashion with the modern idea that the nature of a thing is within it. Because the forms are internal in the way that they are not with Aristotle, the harmony of the world has to be pre-established by God.
Charles Taylor, Sources of the Self: The Making of the Modern Identity
aristotle, god, harmony, leibniz, teleology