In addition to the professional changes, as a virologist he became more cautious and reserved regarding what he knew. From studying his narrative, we see that 'taking control', that lesson from the 1980s and 1990s, is accomplished at two levels: on the communicative level by knowing when to stop talking, and on the strategic level by choosing the right battlefields. It is his habit of selecting the more regulated battlefields that is a very distinct feature of his expert career after the mid-1990s (Goudsmit 2 April 2008) . He chooses spaces he feels comfortable and secure in, spaces that respect the strict boundaries of his expertise. Although these factors are important in understanding why Goudsmit takes up a certain role, in practice the different constituents are difficult to discern. Two loci where he prefers to act are the courtroom and the study, writing popular science books. In a long laudation on his experiences as a courtroom expert, 15 he describes it as the site where expertise is used in the 'purest way possible' outside of science, where all agendas lie open and only the expert's knowledge is questioned. The courtroom enhances the separation of facts and their interpretation; the juridical boundaries create a regulated environment, which is appreciated by Goudsmit (Goudsmit 2 April 2008) .