本文透過對《孟子》、《荀子》文本的細緻解讀，嘗試對孟、荀在人性論上的異同作一重探。本文著力澄清以下課題：1.荀子對孟子性善說的批評並非無的放矢，換言之，從「形式界定」的角度而言，孟、荀對「性善」的理解是一致的，由荀子對「性善」的界定與批評，恰恰可以釐清孟子性善說的實義；2.以孟、荀對「性善」的界定為標準，荀子思想中並無隱含之性善論的主張；3.孟、荀在人性論上的分歧，可歸結為兩種「感應」模式之間的差別，質言之，荀子對孟子所強調的「四端之心」之感應或感通的先天性、直接性與自發性缺乏同情的瞭解，是以在人性的「內容界定」上，孟、荀二家存在重大分歧。

Basing on close reading of ＂Mencius＂ and ＂Xun zi＂, this paper proposes a further reflection on the debate between Mencius and Xun zi, as to whether human nature is inherently good or evil. This paper attempts to discuss the following issues: 1. Xun Zi's argument against Mencius is not ＂always a little off target＂. Instead, from the perspective of formal definition, about the meaning of human nature is good, there is no difference between Mencius and Xun zi. We will also find the true meaning of Mencius' statement that human nature is good from Xun zi's criticism. 2. Take the formal definition of human nature is good as the standard, Xun zi's thought doesn't imply the statement that human nature is good. 3. The root cause of the debate between Mencius and Xun zi about human nature lies within their different understanding of the two models of empathy. In other words, Mencius emphasizes that the moral mind's empathy is transcendental and spontaneous, but Xun zi doesn't agree with such statement. So, from the perspective of the content of human nature, Xun zi is very different from Mencius.