the economic and political theories of Karl Marx and Friedrich Engels that hold that human actions and institutions are economically determined and that class struggle is needed to create historical change and that capitalism will ultimately be superseded by communism
a religious movement of the 16th century that began as an attempt to reform the Roman Catholic Church and resulted in the creation of Protestant churches
improvement (or an intended improvement) in the existing form or condition of institutions or practices etc.; intended to make a striking change for the better in social or political or religious affairs