Scholars and celebrities analyze perceptions of the word from differing perspectives. There has been much analysis of the event from critical sociological and scientific perspectives. There are many reasons for these differences in autobiographical perspectives across cultures. In modern sociological theory, Marxist sociology is recognised as one of the main classical perspectives. It focuses on identifying presuppositions of an abstract nature from varying perspectives. Users can relate variables and build indicators according to their own analytical perspectives. For an overview of criticisms from particular political or philosophical perspectives, see Varieties of criticism. This moved the focus away from mental institutions and traditional clinical perspectives. There are three main theoretical perspectives concerning PES. They consider tyranny from historical, religious, ethical, political and fictional perspectives. New, insightful perspectives and opinions are obtained. Herbartianism refers to the movement underpinned by Herbart's theoretical perspectives. This transition also refocused the fundamental perspectives of each organization. House then divides each epistemological approach into two main political perspectives. There have been critiques of the theory from several perspectives.