Civil society can be understood as the "third sector" of society, distinct from government and business, and including the family and the private sphere. By other authors, civil society is used in the sense of (1) the aggregate of non-governmental organizations and institutions that advance the interests and will of citizens or (2) individuals and organizations in a society which are independent of the government.

Sometimes the term civil society is used in the more general sense of "the elements such as freedom of speech, an independent judiciary, etc., that make up a democratic society" (Collins English Dictionary). Especially in the discussions among thinkers of Eastern and Central Europe, civil society is seen also as a normative concept of civic values.

In his work Politics, the philosopher Aristotle presents the term koinōnía politikḗ (κοινωνία πολιτική), which means a political community, like the city-state (polis), established for collective survival. The telos, or goal of the political community, thus defined, was eudaimonia (τὸ εὖ ζῆν, tò eu zēn), often translated as human flourishing or common well-being, in which man is defined as a 'political (social) animal' (ζῷον πολιτικόν zōon politikón). The concept was used by Roman writers, such as Cicero, where it referred to the ancient notion of a republic (res publica). It re-entered into Western political discourse following one of the late medieval translations of Aristotle's Politics into Latin by Leonardo Bruni, who translated koinōnía politikḗ into societas civilis ("civil society"). With the rise of a distinction between monarchical autonomy and public law, the term then gained currency to denote the corporate estates (Ständestaat) of a feudal ruling class of land-holders, as opposed to the powers exercised by the prince, or monarch. The term civil society has had a long history in state theory and was revived with particular force in the late 20th century in Eastern Europe, where dissidents such as Václav Havel as late as the 1990s employed it to denote the sphere of civic associations threatened by the intrusive holistic state-dominated regimes of Communist Eastern Europe. The first post-modern usage of civil society as denoting political opposition stems from the writings of Aleksander Smolar in 1978–79. However, the term was not used by the Solidarity labor union in 1980–1981.

The ancient Romans were aware of the connections between democracy and a cooperative society, versus a monarchy and a competitive, or uncooperative society. The historian Cassius Dio makes an argument in the voice of Augustus's general Agrippa beseeching Augustus, having defeated his rivals for power in the Roman civil wars, not to overthrow the Roman republic because of its expected effect on society.

The literature on relations between civil society and democratic political society has its immediate origins in Scottish Enlightenment philosophy, including Adam Ferguson's An Essay on the History of Civil Society, and in the work of G. W. F. Hegel, from whom the concepts were adapted by Alexis de Tocqueville, Karl Marx, and Ferdinand Tönnies. They were developed in significant ways by 20th century researchers Gabriel Almond and Sidney Verba, who identified the role of political culture in a democratic order as vital.

They argued that the political element of political organizations facilitates better awareness and a more informed citizenry, who make better voting choices, participate in politics, and hold government more accountable as a result. Civil society acts as a forum for people with common goals and interests to further develop democratic ideals, which in turn can lead to a more democratic state. Membership in these kinds of associations serves as a source of information which reduces the barriers to collective action. These groups then affect policy by putting pressure on governments. This implies that civil society serves to balance the power of the state. The statutes of these political organizations have been considered micro-constitutions because they accustom participants to the formalities of democratic decision making.

More recently, Robert D. Putnam has argued that even non-political organizations in civil society are vital for democracy because they build social capital, trust, and shared values within a society. Social capital, as defined as the social networks and norms of reciprocity associated with them, can help societies resolve dilemmas of collective action; individuals with dense social networks are more likely to credibly commit to other members of society and leverage their social capital to build public goods. In turn, countries with strong civil societies are more likely to succeed as democracies. Some scholars have built on Putnam's claim and argued that the participation of a specific type of civil society organization—non-political organizations rooted in quotidian relationships—in the democratic transition process is what drives successful democratic transitions. Gianfranco Poggi argues this as well, saying that interpersonal trust is needed if republican society is to be maintained.

Others, however, have questioned the link between civil society and robust democracy. As Thomas Carothers points out, civil societies do not necessarily form for worthy reasons nor do they necessarily promote democratic values. For example, Sheri Berman argued that civil society organizations can actually be used to mobilize people against democracy. This was evident in fall of the Weimar Republic in Germany. The Weimar Republic's failure to address the ravages of economic depression, and domestic struggles, led to the creation of a multitude of German civil societies. A defining and arguable fatal flaw of these groups was they reinforced societal conflicts and differences among Germans. This separation of German society into individual social groups meant they were incredibly vulnerable to nationalist ideals. Nazis infiltrated these discontent groups where they eventually became the backbone and foundation for the party and its propaganda. As a result, the Nazi party transformed itself from a place of political irrelevancy in 1928 where they had won 2.63% of the votes to the largest party in the German Reichstag after the 1932 elections. Contrary to Putnam's argument, in this instance, a dense civil society network had damaged democracy. The Nazi Party exploited the societal organization of Germany ultimately leading to the fall of the nation's first ever republic.