In this article the concept of parliamentarism is extended to the concept of ’government by speaking’ (Macaulay 1857), to a political form of rhetorical culture based on arguing for and against. Weber’s relationship to parliamentarism is reassessed in this perspective. The first part deals with his ’parliamentary theory of knowledge’, which refers to his view that the competition of perspectives is constitutive of the human sciences. In this sense the Weberian ideal of scientific practices resembles politics in its openness to change and re-valuation of controversy. In the second part Weber’s critique of anti-parliamentarism is analysed as a rejection of political controversy and struggle. In the third part Weber’s theory of knowledge serves as a point of departure for re-reading his late writings on suffrage, parliamentarism and politicians. The opposition between bureaucracy and politics in particular can be rendered more intelligible in terms of Weber’s ’parliamentary theory of knowledge’.