In his sociology of knowledge, Karl Mannheim postulated a distinction between a morphological, synthesising thought style, and an analytical thought style. A similar distinction, between metaphysical and empirical stances, has recently been made in epistemology and the philosophy of science. This chapter first examines how this divide gained traction in the intellectual and institutional configuration in Red Vienna (1919–1934), where these epistemological/methodological positions were strongly identified as expressions of political positions. In an inversion of the view associated with Critical Theory in which empiricism and positivism were seen as instruments of technological domination, empirical social researchers and members of the ‘left’ Vienna Circle were closely aligned with the Austro-Marxist left, while more speculative, ‘metaphysical’ approaches were associated with the forces of reaction. In this politically polarised context, this view of an epistemological/political divide was shared by both camps. The second part of the chapter explores how the differences between an empirical and analytical approach, on the one hand, and a synthetic and totalising approach, on the other, played out within the early sociology of knowledge itself. It takes Edgar Zilsel and Karl Mannheim as cases on either side of this divide. In the conclusion, the chapter asks, first, whether, in historical retrospect, we need to share the actors’ view at the time that there is a close coupling between epistemological stances or thought styles and political outlook, and, second, whether this empirical/synthetic rift can still be found within and across the social sciences today.