本文討論的張自牧（1833-1886），在晚清的歷史舞臺上，並不是聲名特別顯的士人。不過，在解析晚清「西學源出中國說」這個課題方面，他的兩部論著《瀛海論》與《蠡測卮言》，則屢為史家引徵，他的名諱，遂得以流傳至今；這兩部書，遂亦得在晚清文獻的巨流中居一席之地。本文的寫作，以探討《瀛海論》與《蠡測卮言》這兩部論著的確切寫作年代為目標之一，糾正前此學者（如小野川秀美）誤判其年代的過失。本文論證，這兩部書應當視為一八七○年代末期左右問世論著，史家應該從這個時段的愚想脈絡裡，對它們進行評價與定位。由此，我們更可以從比較寬闊的愚想潮流來認識與理解張自牧的關懷所在，而不再僅視之為研討晚清「西學源出中國說」這個課題的代表人物之一。 以對張自牧著述的考訂為例，筆者並主張，我們對於晚清思想史的研討，必需建立在嚴格的史料批判的基礎上。如此，我們對於晚清時期若干念的變遷流衍，當能有比較明確的認識；評價與反?始可更形深入。

　　　　　Zhang Zimu張自牧(1833-1886) is not a famous literatus in late Qing China, but his two major works, A Discussion of the Cosmos (Yinghia lun瀛海論) and Thoughts from a Small World (Lice zhiyan 蠡測卮言), are often quoted by scholars who analyzed the late Qing discourse of "Western learning (Xixue) originating from China"西學源出中國說This paper provides evidence indicating that Zhang finished his writings in the late 1870's, thus correcting the errors of past historians. For example, Onogawa Hidemi (小野川秀美) suggested that they were finished in the mid-1880's in his shimmatsu seiji shiso kenkyu清末政治思想研究(Studies in the political thought of the late Qing). Using the accurate dating of Zhang Zimu's works as a supporting example study, the author proposes that the study of late Qing intellectual history must be based upon the critical use of historical materials.