This paper examines the implicit foundations of several theoretical propositions characteristic of the Marxist tradition in sociology. It argues that these propositions derive from self-contradictory critical premises which are paradoxes of Action Theory. Implicit in these premises is an ideal picture of social reality quite different from the one analytically described by Parsons. I suggest that Action Theory can provide conceptual tools needed to address some specific issues characteristic of the Marxist perspective and, moreover, offers a solution to some epistemological problems raised by the authors who endorse the postmodern position in social sciences.