The present article treats the manuscript sources as a sort of archive for researches into mentality. It offers an insight into the intellectual heritage of the culture Polish-Lithuanian nobility. Diaries, manuscript books – silva rerum collected news, own notes, excerpts of letters, newspapers etc. At present this kind of private sources can describe a Lost Word of average noblemen. They describe his mental horizons preserving and internalizing system of traditional values and beliefs. Author presented this kind of sources for mentality’s researches at the background of similar notes and manuscript sources in Europe, showing dynamic progress of the European culture of manuscripts.