This article explores the emerging security governance of knowledgeable practices in life sciences and critically reflects on its possible implications. The article first contextualizes the current understanding of the dual-use dilemma in life sciences in prior discourse on science–security relations and argues that security concerns have converged with ethical dilemmas related to the governing of science. Drawing on critical theory, security studies and science studies, it then conceptualizes dual use as a problem of organizing circulations and suggests that policing scientific knowledge through the establishment of a ‘culture of responsibility’ can be understood as a part of broader shifts towards the subjectification of knowledge. Using examples from life sciences, the article analyses how practices of knowledge production and circulation are adjusted to the logic of security.