Tor Andræ’s I myrtenträdgården is the only comprehensive work on sufism written in Swedish language. The concept ”sufism” is interesting when it comes to conceptual shifts and according to Carl W. Ernst, ”sufism” is a westernised construction of an eastern phenomenon. This study examines Andræ's text in the light of Ernst's theory. The aim is to investigate if rhetoric with its theories on topos, fallacies and identification can help us gain insight into this construction and the discussion of sufism in general, and how conceptual shifts takes place in a specific material. The study tells us that Tor Andræ’s I Myrtenträdgården, despite his good intention, shows a hegemonic picture of a sufism with its roots in christianity, a picture that helps to maintain the confusion surrounding the concept. The study also shows that it is mainly through argumentation and identification that this construction takes place. Rhetorical criticism, with its theories, is therefore a fine instrument for highlighting this construction at work.