This thesis set aside conventional occupational distinctions between scientists, administrators and managers, in an examination of social practice within a capitalist State. It explored both the limits of State power and the capacity of State practitioners for transformative action. The central proposition being examined, suggested that State practitioners inevitably engage in forms of action which tend to perpetuate existing social and economic relationships. The epistemology of Jurgen Habermas provided the framework for this analysis in which distinctions were made between different forms of scientific enquiry and corresponding modes of social action. These distinctions equated the empirical-analytic tradition with strategic action, the historical-hermeneutic tradition with communicative action, and the critical tradition with emancipatory action. Distinctions were also made between two alternative but related levels of practice; namely, interaction, defined as the communicative and strategic actions of knowledgeable participating subjects, and societal action which emanates out of the forces and relations of production and which represents the institutionalisation of behavioural patterns established by society as a whole. In an examination of the social indicators movement it was revealed that crucial questions relating to economic and political structures interest group manoeuvrings, and social conflict in general, had been omitted. Practitioners appeared to exclude the possibility of political motivation from both the design and construction of social indicator systems. By accepting the structural limitations imposed by capitalist economic and social relations and by agreeing to operate within the selective limitations established by the dominant class, practitioners inadvertently aligned themselves with the empirical tradition and with strategic action. Although the Habermasian distinctions between different scientific traditions proved adequate in evaluating the outcome of practice, it was necessary to reappraise the theoretical logic of class so as to account for those locations within the State which could not be defined by ownership of the means of production. This reappraisal identified practitioners as members of the auxiliary class occupying contradictory locations between the proletariat and the bourgeoisie. Whereas bourgeois and proletarian locations are occupied by classes which are diametrically opposed, the auxiliary class draws its characterictics from a simultaneous and partial location in two classes. As a consequence, the class actions of State practitioners are infused with ambiguities. These ambiguities became evident when the examination focussed on strategic and communicative action. Although the cognitive interests of the auxiliary class seemed to coincide with the values and interests of the bourgeoisie any instrumental association between the actions of State practitoners and the dominant class was rendered problematic. Whereas the cognitive interests of State practitioners exemplified the distinctive characteristics of different forms of knowledge, the class practices in which they engaged stemmed from their structural locations within the State, their contradictory class interests, and their mediating capacities. These mediating capacities were examined by analysing the practices of an N.R.A.C. Working Party which was commissioned to report on unemployment. Although the Working Party demonstrated the potential of the critical tradition for transformative practice, the expression of this theorem in action was less than conclusive. Whilst the Working Party displayed a primary interest in the emancipation of those disadvantaged by unemployment, the contradictions identified in the report were displaced by the dominant class and by State managers around the boundary of the bourgeoisie. Although the cognitive interests of the Working Party were consistent with the critical tradition, there was no evidence to suggest that the practices of the Working Party promoted either personal or political emancipation. Thus any instrumental association between the critical tradition and emancipatory action could not be sustained. As a consequence of these examinations it became apparent that the central reality for practitioners within the State was the contradictory nature of practice. Habermasian theory was then extended in an attempt to resolve the problematic relationship between theory and practice.