專業研究者之外，一般讀者對於歷史事件的認識，通常不是來自專業史書。但是若就專業史書而言，簡明的現代史可能是相對嚴謹的資訊來源。為理解歷史認知的真實模樣，本文以曾國藩和他的湘軍為主題，安排現代史、專門著作及曾國藩家書三個層次的歷史紀錄，交互呈現同一主題之不同面貌。家書之選擇被列為最底層歷史，是因為家書不同於公開文書，其中若干紀實可能與現代史或專書之間呈現不連續的現象，適可彌補、甚至修正前者過於凝鍊的印象。然而此一「三層閱讀」終究不是一般讀者在興趣及時間上可普遍進行的，所以「何謂歷史」之基本議題，對任一社會之大眾而言依舊構成問題。 Ordinary people are not professional researchers, their knowledge of historical events usually doesn't come from formal historical writings. Among such writings, relatively, concise modern history may be the most popular resource. In order to understand the real formation of historical knowledge, this paper arranges three levels of history, which are modern history, professional historical book or paper, and family letters of Tseng Kuo-Fan, to focus on the same topic "Tseng Kuo-Fan and his Hunan Army". By comparing three ways the same story goes, private letter to family would reveal some record which may be discontinuous to the image derived from modern histories and books. Such "three-level historical reading" offers the possibility to retrieve our historical knowledge. However, this way of reading is not affordable to ordinary people. "What is history" would, perhaps, be eternally problematic to any human society.
