According to major philosophical thinkers, do we need social contracts to maintain order in society, or can we rely on human nature?
Whether a given philosopher believes that humanity in a state of nature can construct a just and stable society depends on that philosopher's concept of human nature.
Thomas Hobbes can with some fairness be described as a Calvinist without a God. He considers humanity totally corrupt and fallen, and in its natural state constantly at war, living a life "nasty, brutish, and short." Only by having a strong absolute power enforcing social contracts can society function at all.
Jean Jacques Rousseau has a far more optimistic account of human nature, believing that we are inherently good and only spoiled by civilization, and thus do not need an authoritarian government.