In this paper I focus on the Hungarian intellectual and politician Paul Szende's sociologically oriented epistemology. I trace the influences of physiology, psychology, economy, evolutionary theory of his day on his sociological theory of abstractive knowledge, and discuss the close connection between physiological, social, and economic aspects in the early sociology of knowledge. My discussion continues with an examination of Szende's differentiation between two economic effects within social epistemology: on the one hand the "economy of thought' in the tradition of Ernst Mach, with its physiological, organic, and integrative functioning of knowledge; on the other hand, the socio-economic effects of social selection, exclusion, and societal antagonism. Besides the Marxist and more specifically the Austro-Marxist environment of Szende's writings, I trace the influence of the economic theory of Italian economist Achille Loria on Szende's understanding of the antagonistic nature of the transformation of knowledge. The paper is set at the intersection of philosophy of science and history of science. It relates epistemological issues to historical, social, and scientific developments in Szende's day and thus combines a philosophical analysis of Szende's sociological theory of knowledge with historical research into the natural, social, and economic sciences of his time.