「性善論」，是一意涵不甚清晰的語詞；而「孟子性善論」則是內審不易完全掌握的立論。本文希望透過語意的分析與恰當的分類，以釐清「性善論」之意涵，並依《孟子》原典作歸納，以使「孟子性善論」的內容，能較爲具體如實地呈顯。首言「性」、「善」的分類與意涵；次從各種切入面以說明「性」與「善」的可能關係；然後說明最究竟義「性善說」的意涵、內在屬性與呈現樣態等；最後則舉《孟子》原典，以衡定「孟子性善說」較為可能之意涵。經由本文探析所得出之「孟子性善論」意涵爲：所有人天生「皆具」且「皆具」善的道德性，這種道德性與聖人「同質等量」，且會剎那的呈顯於我們生命中。

"Shing Shan Lun" refers to words and phrases with unclear meaning. "Meng'tze's Shing Shan Lun" refers to an argumentation which contents cannot be grasped completely. This paper aims to clarify the meaning of "Shing Shan Lun" through semantic analysis and appropriate classification, and uses the original version of "Meng-tze" to substantially and truthfully present the contents of "Meng'tze's Shing Shan Lun". This paper first discusses the classification and meaning of "Shing" and "Shan", then explains the possible relationships of "Shing" and "Shan" from different perspectives, as well as the meaning, inner attributes, and presentation pf "Shing Shan Shuo", lastly, concluding the most possible meaning of "Meng'tze's Shing Shan Lun" by referring to the original version of "Meng-tze". This paper concludes that the meaning of "Meng'tze's Shing Shan Lun" is that all humans are born with and always possess the virtue of righteousness, and such virtue is equivalent to that possesses by saints, and appears in our life in split seconds.