The social revolutions that have occurred spasmodically throughout history are an important area of study, forming a distinct and drastic pattern of sociological change.. Unique to social revolutions is that basic changes in social structure and political structure occur together in a mutually reinforcing pattern, and it can be asserted with a fair degree of accuracy that changes occur through socio-political conflicts in which class struggles do play a role.
In studying revolutions, the use of theory has been employed in an attempt to provide an explanation (within a context) that enables us to predict for the future which consequences should follow which events. Theories over the causes, course and consequences of revolution have developed significantly; early theories becoming limited in their aims and objectives. Instead, today comparative historical methods are a major influence on theoretical interpretation of revolution that gives breadth from the use of examples.
The main difficulty encountered by historians in attempting to generalise revolutions using the theoretical approach has been the failure to test and modify explanations in light of subsequent historical cases. This makes the theory unfalsifiable and therefore unvarifiable – limiting the extent that they can really be relevant to such an important and broad area of history.
Despite this, many prominent historians have made attempts at formulating such theories, one of the most successful of which was Karl Marx. He saw revolutions not as isolated episodes of violence, but instead, a class based movement growing out of 'objective structural contradictions within historically developing, and essentially conflict ridden, societies'. Therefore, Marx saw the key to society as being the relationships to a mode of production.
Revolutions specifically emerge when a new socio-economic structure emerges, thus creating growth of unity and class-consciousness. Prominent examples in the 19th century, which came to form the basis of many such theories, were transitions such as capitalism from feudalism, and socialism from capitalism. These largely encompassed ongoing struggles between the dominant class and the majority, and in this way revolution was accomplished through class action led by self-consciousness.
The rising revolutionary classes came about through the evolution of class divided modes of production, and the transforming of one mode of production into another through industrial revolution and class conflict. Marx's theory has, however been criticised by John Elster, who argues that 'Marx provided no rational grounds for thinking that events would develop as he hoped. His scenarios were, essentially, based on wishful thinking, and 'not on social analysis', a vital component in formulating a relevant and maintainable theory.
Following Marxist theory, which laid the basis for a political theory to have major repercussions throughout Europe, there have been three other major theories dealing with revolution, and these do provide and economical way of identifying relevant basic theoretical issues in a summarising and general medium for later commentary. Therefore, 3 major theories have arisen: 1) Aggregate-psychological theories, Gurr 'Why Men Rebel', Wolfenstein 2) Social structural theories, Johnson's Revolutionary Change theory 3) Political conflict theories, Tilly – From Mobilisation to Revolution
Aggregate-psychological theories explain revolutions in terms of people's psychological motivations for engaging in political violence or joining opposition movements and are exemplified in Ted Gurr's 'Why Men Rebel'. This psychologically based theory sees political violence as all collective attacks within a political community against the political regime and identifies political violence occurring when there is a gap between the valued things they felt entitled to and what they get, described as ' relative deprivation'.
Revolutions come about following widespread, intense and multi-faceted relative deprivation affecting the aspirations of the masses and the elites. It is according to this theory that when both potential leaders and followers are frustrated that the conditions for internal war are present. However this theory is limited in its assumptions that people will behave in the same way and crowd action has played little role in revolution since France in 1789.
Wolfenstein's theory, which sought to explain revolution in terms of personality have also failed as it is not possible to apply clinical methods to past political leaders and it appears only valuable to look at the role of leader in a wider social context. Having said this, Gurr's ideas of relative deprivation do help in understanding a major aspect of revolution in giving a greater insight into what gives rise to discontent. Systems/Value Consensus theories explain revolutions as violent responses of ideological movements to severe disequilibrium in social systems.