This paper presents a normative pragmatics analysis of students' use of science content in eight socioscientific group discussions about human gene therapy. The specific focus of the paper is on the argumentative role that invocations of science had in the dialectics of the discussions. The analysis suggests that science content occasionally played an informative role in attempts to establish the factual background of parts of the deliberations, but that speakers often invoked science content creatively and selectively in argumentative strategies that aligned with an attempt to frame the issue of the discussion in ways that were favorable for the speaker. The paper aims at explaining how strategies that contained invocations of science worked pragmatically in the dialectical context of the discussions. The findings are discussed in relation to previous findings in the science education community as well as to more general questions pertaining to how science fits into socioscientific discussions in which the arguers deliberate about what to do, not just what is true. © 2012 Wiley Periodicals, Inc. Sci Ed 96:428–456, 2012