Unger's philosophy of space and time presented in The Singular Universe and the Reality of Time argues for the singularity of the world and the reality of time. His arguments are grounded in the tradition of natural philosophy. He takes on the Newtonian idea of the independent observer standing outside of time and space, addresses the skepticism of David Hume, rejects the position of Kant, and attacks speculations about parallel universes of contemporary cosmology. At stake is the laying of the foundations for a view of the world and causality that is open to all possibilities; that is not a closed system of options in which our future is governed by deterministic laws and typologies. It is an understanding of society that rejects the naturalness and necessity of current social arrangements; "a form of understanding of society and history that refuses to explain the present arrangements in a manner that vindicates their naturalness and necessity."