RARE FIRST EDITION of the first original work by a living author in Irish. The few works printed in Irish appearing prior to this were the Bible, liturgy, or translations of the works of others. This is one of a small group of books from the first press to print and promote Irish writing in the vernacular. Active from 1614-1618, it issued five books. The press was an outgrowth of a concentration of scholars skilled in Irish and other languages at St. Anthony's, the Franciscan college at Louvain, which acquired the press in 1611. Though their primary purpose was to train priests for the Irish and Scottish missions, they also published literary works for a wider Irish audience, later using commercial publishers (after the demise of this press). MacCaghwell came from an old Irish family. He was born in Co. Tyrone and early in life entered the service of Hiugh O'Neill, earl of Tyrone, as tutor to his sons. In 1604 in Spain he entered the Franciscans, and in 1606 went to the Spanish Netherlands where he set up the Franciscan College in Louvain, and played an active role in Irish spiritual and intellectual life.
For the publication of this work the author used his Irish name Aodh Mac Aingil, although the Latin form of his name is given at the end of the book. The title means ‘A mirror of the sacrament of penance’, and the work is devotional in nature. "Although this acknowledged James I as the rightful ruler of Ireland, it also identified Ireland as a Catholic nation and demonstrates a very modern sense of national consciousness. Moreover, the work is a prominent example of how the literary language of contemporary Irish poets was used to produce a readable prose text" (Terry Clavin in ODNB).