Hobbes vs. Rousseau
Overview
The English philosopher Thomas Hobbes (1588.04.05 - 1679.12-04) argued (in essence) that humans are bad, and that therefore assertion of authority is necessary in order to prevent civil chaos.
This viewpoint was also expanded upon and criticized by English philosopher John Locke (1632.08.29 - 1704.10.28). Locke agreed with Hobbes that people are often selfish, but (unlike Hobbes) also believed that human nature is characterized by reason and tolerance; the combination of these ideas is sometimes called enlightened self-interest. Locke's ideas figured significantly in the Enlightenment, strongly influenced the founding fathers of the United States of America, and also figured prominently in the thinking of later philosophers including Rousseau.
Swiss philosopher Jean-Jacques Rousseau (1712.06.28 - 1778.07.02) argued that that humans are good by nature but are corrupted by society.
Rousseau also argued that the state of nature eventually degenerates into a brutish condition without law or morality, at which point the human race must adopt institutions of law or perish – seemingly agreeing with Hobbes on the necessity for imposition of authority – but also believed that sovereignty should be in the hands of the people, while Hobbes apparently felt that the nature of the relationship should be rather looser, with the sovereign having only a "moral obligation" to make good decisions.
The opposing viewpoints of Hobbes and Rousseau often arise in discussions of political philosophy and are typically referred to as Hobbes vs. Rousseau.