There are several contradictory formulations of System paradigm in Kornai. It was used both in terms of GET and its opposite. It was also used in a Marxian way and then was transformed to something opposite to materialist conception of history. Economic systems theory was initially supposed to be exempt from political economy (political neutrality), but it was later reinterpreted as a new basis for political economy. Two broad orientations might be distinguished: 1) Economic perspective: Economic systems theory explaining an ‘order’ in the context of Walrasian or Marshallian Equilibrium (disequilibrium) 2) Institutional perspective: Economic systems theory as political economy of ‘great systems’