Marwick’s model comprises four principal components: major forces and
constraints, events, human agents, and convergences and contingencies.
Major forces and constraints (that is, structures) are of three main forms: structural (for example, geographical, demographic, economic and technological),
ideological (for example, what is believed and can be believed, existing political and social philosophies),
and institutional (for example, systems of government, justice, policing and voting, educational, religious and working-class organisations and the family).