多元，在社会科学中，指不同种族、民族、宗教或社会群体在一个共同文明体或共同社会的框架下，持续并自主地参与及发展自有传统文化或利益。

在多元社会中，不同族群相互间展示尊重与容纳，从而使他们可以安乐共存、相互间没有冲突或同化。许多人认为多元是现代社会的最重要特征之一，也是科学、社会、经济等发展的关键性推动力量。

在威权主义或寡头政治的社会，权力高度集中，各项决定由少数人做出。在多元社会，权力、决策过程及利益分享相对较为分散。人们相信这样可以鼓励社会成员更广泛的参与、更大的约束感、以及更佳的成效。比如，多元主义对下列情形是重要的：公司、政治体、经济体、科学界。在科研过程，多元主义是知识快速增长的重要因素。返回来，知识增长可以通过提高生产力、经济增长、改善医疗等来增进人类福利。

Classical pluralism is the view that politics and decision making are located mostly in the framework of government, but that many non-governmental groups use their resources to exert influence. The central question for classical pluralism is how power and influence are distributed in a political process. Groups of individuals try to maximize their interests. Lines of conflict are multiple and shifting as power is a continuous bargaining process between competing groups. There may be inequalities but they tend to be distributed and evened out by the various forms and distributions of resources throughout a population. Any change under this view will be slow and incremental, as groups have different interests and may act as "veto groups" to destroy legislation. The existence of diverse and competing interests is the basis for a democratic equilibrium, and is crucial for the obtaining of goals by individuals. A polyarchy – a situation of open competition for electoral support within a significant part of the adult population − ensures competition of group interests and relative equality. Pluralists stress civil rights, such as freedom of expression and organization, and an electoral system with at least two parties. On the other hand, since the participants in this process constitute only a tiny fraction of the populace, the public acts mainly as bystanders. This is not necessarily undesirable for two reasons: (1) it may be representative of a population content with the political happenings, or (2) political issues require continuous and expert attention, which the average citizen may not have.