Conflict theories are perspectives in sociology and social psychology that emphasize a materialist interpretation of history, dialectical method of analysis, a critical stance toward existing social arrangements, and political program of revolution or, at least, reform. Conflict theories draw attention to power differentials, such as class conflict, and generally contrast historically dominant ideologies. It is therefore a macro-level analysis of society.
Karl Marx is regarded as the father of social conflict theory, which is a component of the four major paradigms of sociology. Certain conflict theories set out to highlight the ideological aspects inherent in traditional thought. While many of these perspectives hold parallels, conflict theory does not refer to a unified school of thought, and should not be confused with, for instance, peace and conflict studies, or any other specific theory of social conflict.
In classical sociology
Of the classical founders of social science, conflict theory is most commonly associated with Karl Marx (1818–1883). Based on a dialectical materialist account of history, Marxism posited that capitalism, like previous socioeconomic systems, would inevitably produce internal tensions leading to its own destruction. Marx ushered in radical change, advocating proletarian revolution and freedom from the ruling classes. At the same time, Karl Marx was aware that most of the people living in capitalist societies did not see how the system shaped the entire operation of society. Just as modern individuals see private property (and the right to pass that property on to their children) as natural, many of the members in capitalistic societies see the rich as having earned their wealth through hard work and education, while seeing the poor as lacking in skill and initiative. Marx rejected this type of thinking and termed it false consciousness, the use of misdirection by the ruling class to obfuscate the exploitation intrinsic to the relationship between the proletariat and the ruling class. Marx wanted to replace this false consciousness with something Friedrich Engels termed class consciousness, the workers’ recognition of themselves as a class unified in opposition to capitalists and ultimately to the capitalist system itself. In general, Marx wanted the proletarians to rise up against the capitalists and overthrow the capitalist system.
The history of all hitherto existing society is the history of class struggles. Freeman and slave, patrician and plebeian, lord and serf, guild-master and journeyman, in a word, oppressor and oppressed, stood in constant opposition to one another, carried on an uninterrupted, now hidden, now open fight, a fight that each time ended, either in a revolutionary re-constitution of society at large, or in the common ruin of the contending classes.— Karl Marx & Friedrich Engels The Communist Manifesto 1848, 
In the social productions of their existence, men inevitably enter into definite relations, which are independent of their will, namely relations of production appropriate to a given stage in the development of their material forces of production. The totality of these relations of production constitutes the economic structure of society, the real foundation, on which arises a legal and political superstructure and to which correspond definite forms of social consciousness. The mode of production of material life conditions the general process of social, political and intellectual life. It is not the consciousness of men that determines their existence, but their social existence that determines their consciousness. At a certain stage of development, the material productive forces of society come into conflict with the existing relations of production or – this merely expresses the same thing in legal terms – with the property relations within the framework of which they have operated hitherto. From forms of development of the productive forces, these relations turn into their fetters. Then an era of social revolution begins. The changes in the economic foundation lead sooner or later to the transformation of the whole immense superstructure.
In studying such transformations it is always necessary to distinguish between the material transformation of the economic conditions of production, which can be determined with the precision of natural science, and the legal, political, religious, artistic or philosophic – in short, ideological forms in which men become conscious of this conflict and fight it out. Just as one does not judge an individual by what he thinks about himself, so one cannot judge such a period of transformation by its consciousness, but, on the contrary, this consciousness must be explained from the contradictions of material life, from the conflict existing between the social forces of production and the relations of production. No social order is ever destroyed before all the productive forces for which it is sufficient have been developed, and new superior relations of production never replace older ones before the material conditions for their existence have matured within the framework of the old society.
Mankind thus inevitably sets itself only such tasks as it is able to solve, since closer examination will always show that the problem itself arises only when the material conditions for its solution are already present or at least in the course of formation. In broad outline, the Asiatic, ancient, [a] feudal and modern bourgeois modes of production may be designated as epochs marking progress in the economic development of society. The bourgeois mode of production is the last antagonistic form of the social process of production – antagonistic not in the sense of individual antagonism but of an antagonism that emanates from the individuals’ social conditions of existence – but the productive forces developing within bourgeois society create also the material conditions for a solution of this antagonism. The prehistory of human society accordingly closes with this social formation.— Karl Marx A Contribution to the Critique of Political Economy 1859, 
Two early conflict theorists were the Polish-Austrian sociologist and political theorist Ludwig Gumplowicz (1838–1909) and the American sociologist and paleontologist Lester F. Ward (1841–1913). Although Ward and Gumplowicz developed their theories independently they had much in common and approached conflict from a comprehensive anthropological and evolutionary point-of-view as opposed to Marx’s rather exclusive focus on economic factors.
Gumplowicz, in Grundriss der Soziologie (Outlines of Sociology, 1884), describes how civilization has been shaped by conflict between cultures and ethnic groups. Gumplowicz theorized that large complex human societies evolved from the war and conquest. The winner of a war would enslave the losers; eventually a complex caste system develops. Horowitz says that Gumplowicz understood conflict in all its forms: “class conflict, race conflict and ethnic conflict”, and calls him one of the fathers of conflict theory.
What happened in India, Babylon, Egypt, Greece and Rome may sometime happen in modern Europe. European civilization may perish, over flooded by barbaric tribes. But if any one believes that we are safe from such catastrophes he is perhaps yielding to an all too optimistic delusion. There are no barbaric tribes in our neighbourhood to be sure — but let no one be deceived, their instincts lie latent in the populace of European states.— Gumplowicz (1884), 
Ward directly attacked and attempted to systematically refute the elite business class’ laissez-faire philosophy as espoused by the hugely popular social philosopher Herbert Spencer. Ward’s Dynamic Sociology (1883) was an extended thesis on how to reduce conflict and competition in society and thus optimize human progress. At the most basic level Ward saw human nature itself to be deeply conflicted between self-aggrandizement and altruism, between emotion and intellect, and between male and female. These conflicts would be then reflected in society and Ward assumed there had been a “perpetual and vigorous struggle” among various “social forces” that shaped civilization. Ward was more optimistic than Marx and Gumplowicz and believed that it was possible to build on and reform present social structures with the help of sociological analysis.
Émile Durkheim (1858–1917) saw society as a functioning organism. Functionalism concerns “the effort to impute, as rigorously as possible, to each feature, custom, or practice, its effect on the functioning of a supposedly stable, cohesive system,” The chief form of social conflict that Durkheim addressed was crime. Durkheim saw crime as “a factor in public health, an integral part of all healthy societies.” The collective conscience defines certain acts as “criminal.” Crime thus plays a role in the evolution of morality and law: “[it] implies not only that the way remains open to necessary changes but that in certain cases it directly prepares these changes.”
Max Weber’s (1864–1920) approach to conflict is contrasted with that of Marx. While Marx focused on the way individual behaviour is conditioned by social structure, Weber emphasized the importance of “social action,” i.e., the ability of individuals to affect their social relationships.
C. Wright Mills has been called the founder of modern conflict theory. In Mills’s view, social structures are created through conflict between people with differing interests and resources. Individuals and resources, in turn, are influenced by these structures and by the “unequal distribution of power and resources in the society.” The power elite of American society, (i.e., the military–industrial complex) had “emerged from the fusion of the corporate elite, the Pentagon, and the executive branch of government.” Mills argued that the interests of this elite were opposed to those of the people. He theorized that the policies of the power elite would result in “increased escalation of conflict, production of weapons of mass destruction, and possibly the annihilation of the human race.”
Gene Sharp (1928-2018) was a professor emeritus of political science at the University of Massachusetts Dartmouth. He is known for his extensive writings on nonviolent struggle, which have influenced numerous anti-government resistance movements around the world. In 1983 he founded the Albert Einstein Institution, a non-profit organization devoted to studies and promotion of the use of nonviolent action in conflicts worldwide. Sharp’s key theme is that power is not monolithic; that is, it does not derive from some intrinsic quality of those who are in power. For Sharp, political power, the power of any state—regardless of its particular structural organization—ultimately derives from the subjects of the state. His fundamental belief is that any power structure relies upon the subjects’ obedience to the orders of the ruler or rulers. If subjects do not obey, leaders have no power. Sharp has been called both the “Machiavelli of nonviolence” and the “Clausewitz of nonviolent warfare.” Sharp’s scholarship has influenced resistance organizations around the world. More recently, the protest movement that toppled President Mubarak of Egypt drew extensively on his ideas, as well as the youth movement in Tunisia, and the earlier ones in the Eastern European colour revolutions that had previously been inspired by Sharp’s work.
A recent articulation of conflict theory is found in Canadian sociologist Alan Sears’ book A Good Book, in Theory: A Guide to Theoretical Thinking (2008):
- Societies are defined by inequality that produces conflict, rather than which produces order and consensus. This conflict based on inequality can only be overcome through a fundamental transformation of the existing relations in the society, and is productive of new social relations.
- The disadvantaged have structural interests that run counter to the status quo, which, once they are assumed, will lead to social change. Thus, they are viewed as agents of change rather than objects one should feel sympathy for.
- Human potential (e.g., capacity for creativity) is suppressed by conditions of exploitation and oppression, which are necessary in any society with an unequal division of labour. These and other qualities do not necessarily have to be stunted due to the requirements of the so-called “civilizing process,” or “functional necessity”: creativity is actually an engine for economic development and change.
- The role of theory is in realizing human potential and transforming society, rather than maintaining the power structure. The opposite aim of theory would be the objectivity and detachment associated with positivism, where theory is a neutral, explanatory tool.
- Consensus is a euphemism for ideology. Genuine consensus is not achieved, rather the more powerful in societies are able to impose their conceptions on others and have them accept their discourses. Consensus does not preserve social order, it entrenches stratification, a tool of the current social order.
- The State serves the particular interests of the most powerful while claiming to represent the interests of all. Representation of disadvantaged groups in State processes may cultivate the notion of full participation, but this is an illusion/ideology.
- Inequality on a global level is characterized by the purposeful underdevelopment of Third World countries, both during colonization and after national independence. The global system (i.e., development agencies such as World Bank and International Monetary Fund) benefits the most powerful countries and multi-national corporations, rather than the subjects of development, through economic, political, and military actions.
Although Sears associates the conflict theory approach with Marxism, he argues that it is the foundation for much “feminist, post-modernist, anti-racist, and lesbian-gay liberationist theories.”
Conflict theory has three assumptions:
- Humans are self-interested.
- Societies operate under perpetual scarcity of resources.
- Conflict is pervasive and unavoidable within social groups and between social groups.
Conflict theory is most commonly associated with Marxism, but as a reaction to functionalism and the positivist method, it may also be associated with a number of other perspectives, including:
- Critical theory
- Feminist theory: An approach that recognizes women’s political, social, and economic equality to men.
- Postmodern theory: An approach that is critical of modernism, with a mistrust of grand theories and ideologies.
- Post-structural theory
- Postcolonial theory
- Queer theory: A growing body of research findings that challenges the heterosexual bias in Western society.
- World systems theory
- Race-Conflict Approach: A point of view that focuses on inequality and conflict between people of different racial and ethnic categories.
- Critical realism (philosophy of the social sciences)