這篇論文以吉朋（Edward Gibbon, 1737–1794）《羅馬帝國衰亡史》（以下簡稱《衰亡史》）前三卷之註腳作為分析對象，探討吉朋如何使用註腳，藉以了解吉朋書寫《衰亡史》背後的史學思維。吉朋在《衰亡史》中大量使用「註腳」，將近八千個，支撐其羅馬帝國史的宏觀敘述。這些註腳的內容多元，文字豐富，佔《衰亡史》篇幅近四分之一。吉朋使用註腳的手法高明，將其功能發揮到淋漓盡致。除了基本的史學徵信功能，吉朋在註腳說明資料選擇原則、處理方式，或進行考訂與論證。有些情境不便在正文表述，吉朋選擇在註腳中揭露，兼顧歷史真實與敘事的文雅。他也利用註腳與古人對話，與近人論辯，進行今古比較，猶如一個桌上論壇。由此可知，吉朋的註腳隱藏他的許多歷史思維。

This article discusses the use Edward Gibbon made of footnotes in his writing of The History of the Decline and Fall of the Roman Empire, focusing on the first three volumes of the works, with a view to grasping the historical thinking that lies behind his composition of the Roman history. There are nearly 8,000 footnotes in the History, which represent, in terms of words, around a quarter of its contents. Gibbon was a great master of the art of the footnote and the manifold and masterly ways in which he composed them contribute not only to evincing the credentials, but also to highlighting the art, of his narration of the decline and fall the Roman Empire. In addition to the basic function of proving his credentials as an historian, Gibbon had, in his footnotes, explained his principle of selecting sources, his ways of using materials and the criticism he made on them when necessary. Moreover, in the age of politeness, contents considered not proper to appear in the main texts, Gibbon would choose to hide them in the footnotes instead, so that historical truth and the decency of writings could both be attended to. Gibbon also often used footnotes to have dialogues with the ancient authors he had cited and to argue against the modern historians he disagreed with. It amounts to a sort of table-talk which would enliven Gibbon’s narration of the decline and fall of the Roman empire.