Comparison of Two Press Theories. Of the four theories of the mass media made famous by Siebert et. al., this essay will focus on two, namely the Authoritarian Theory and the Libertarian Theory. Based on an analysis of the 'Proposed Equation' between ideology as such and the Theories of the Mass Media, a comparison of these two theories will be delved into in this essay. Pages: 9 Bibliography: 5 source(s) listed Filename: 17726 Comparison Press Theories.doc Price: 80.55