Most Students and many scholars seem to believe that for the Renaissance, as well as for other periods of Western history, the relevant source material is adequately known, and that all there remains to be done is to reinterpret and to correlate these wellknown sources and to fit them into a comprehensive picture. Unfortunately, or fortunately, this complacent view does not correspond to the actual state of affairs. In the field of humanist literature and thought, on which I have focused my attention for twenty years or so (that is, in the area of literary, scholarly and philosophical works in Latin produced in Italy between 1300 and 1600), many extant authors, and even many writings of well-known authors are not listed in the best available reference works, and even some of the most famous writings have not yet been published in critical editions, or adequately explored as to their chronology and textual history.