Seven works by the Buddhist philosopher Dharmakīrti (ca. 600–660 CE) are still nearly completely extant in their original Sanskrit. For the most part they deal with logic, theories of perception and Buddhism. The Pramāṇavārttikam with its prose self-commentary (Svavṛtti), consisting of four chapters, is considered an early composition of Dharmakīrti and is without doubt his most important work. In the first chapter of the Pramāṇavārttikam, Dharmakīrti devotes himself to a long excursus concerning the substantiation of scriptural authority (āgamaprāmāṇya). Here the famous Indian logician presents his own thoughts and enters a long contestation with the orthodox and ritual-oriented Mīmāṃsā School. The main part of the present study is an annotated translation into French of the verses 213–268 and their respective commentary. The translation has been undertaken from a historical as well as intellectual perspective and includes several appendixes (among them a critical edition of the Tibetian version of the passage). This volume presents both the first translation of this section of the Pramāṇavārttikam into a Western language and a first fundamental discussion of the doctrines contained therein. The study also intends to appraise more closely the importance of Dharmakīrti's works from their historical and ideological as well as their traditional context.