This article examines how August Strindberg's scientific interest feeds into his literary work. The analysis focuses on the autobiographically inspired novel "Le Plaidoyer d'un fou", which Strindberg wrote directly in French, and compares it to the first German translation, which was the first ever publication of this novel. The analysis reveals that readers of the translation did not get a faithful picture of the function Strindberg ascribes to psychology in the novel. This was not without consequence for the Swedish reception of "Le Plaidoyer". In fact, the first two Swedish translations of the novel were not based on Strindberg's original French manuscript, but on the first German translation. Further studies will look at how various translators of "Le Plaidoyer d'un fou" dealt with the challenges of reproducing Strindberg's French style in their respective target languages, with a particular focus on Swedish.