A partial reprint of the text by Nicolau Eymerich (1376) with commentaries and additions by Francisco Peña (1578). A collection of instructions for the use of Inquisition officials, including descriptions of the victims of persecution (e.g. heretics, Conversos, etc.), procedures to be followed (e.g. denunciation, investigation, interrogation, sentencing), as well as the powers invested in the Inquisitors (e.g. torture, imprisonment, confiscation). The preface to this edition (p. 9-28), by Leonardo Boff, denounces the Inquisition as an intolerant, un-Christian institution, established to eradicate all that is different.