The Specimina philosophiae (Amsterdam: Elzevier, 1644) are preceded by a notice in which Descartes authorizes the text as a faithful translation of his Discours and Essais, and announces that he has made some changes in the original content. This raises questions about the nature, extent and background of these authorial interventions-questions that are all the more important because until well into the 19th century, the Latin version reached a far larger audience than the French text. Nonetheless, the differences between both texts had never been researched systematically. Corinna Vermeulen's thesis fills this lacuna, while also providing the first critical edition of the Specimina. The first chapter of the Introduction discusses the historical background of the translation, especially its link to the intended Latin publication of the objections and replies following the Discours and Essais, the identity of the translator, and the question as to why the Geometrie was not included in the translation. Chapter 2 goes into the printing and distribution of the text, which is connected to that of the Principia philosophiae. Vermeulen provides and interprets a variety of sources, some hitherto unknown, to shed new light on this part of the history of Descartes's works. Chapter 3 deals with the relation between the Specimina and their source text, analysing the translation's style against the background of contemporary translation theory and practice. It is shown that the translation is far from faithful, despite Descartes's claim to the contrary. The tools, stylistic and otherwise, which the translator used in order to adapt the text to its new audience are categorized and discussed. Special attention is given to the strategic modification of theologically problematic passages, and to Jacobus Revius' criticism of this procedure. Sifting through the many translator's liberties, Vermeulen highlights probable and certain authorial interventions, and where possible provides a background from Descartes's correspondence and ...