This article examines issues related to competition within the domain of Siddha medicine ( citta maruttuvam ), that is, Tamil medicine. It focuses on the tension and co - constitution of the figure of the hereditary Siddha practitioner and the college -educated Siddha practitioner. Based on ethnographic interviews conducted in South India, it analyzes how the figure of the hereditary Siddha practitioner is semantically delineated in the aftermath of the formal professionalization of Siddha medicine. Based on the assumption that practices of self -representation and broader social structures form a constitutive relationship, it discusses the interlocutors’ accounts as semantic positionings in a ‘strategic action field’ (Fligstein/McAdam 2012). Accordingly, the article suggests that the interlocutors’ distinct self -fashioning, especially their appropriation and fusion of religious and scientific semantics, be conceptualized as a strategic improvisation that establishes and ensures them a favorable position in this particular social field.