宋代新儒人物由於早年出入釋老的經歷，因此較能從思想內容上與佛教展開對話。其中，以朱子對佛教思想的探究最為深入，因此最值得注意。雖然如此，朱子的理解內容與佛教原義仍有差距。本文以「性空」思想為中心加以探究，發現朱子以「沒有天理內涵」理解「性空」，確非佛教「無自性」之意。朱子理解誤差的原因，在於從「性即理」的觀點來看佛教的「性空」，將佛教蕩相遣執的作用誤解為存有論的內容建構。雖然對佛教「性空」原義不契，但若就儒家以「道德」作為對性的實質規定，與佛教以「空」作為對性之執見的解消、不欲有實質內涵的建立而言，朱子「儒實釋虛」的分判大體上是不錯的；而據「虛」與「實」的分判來看儒學者者的工夫深淺，則表現出朱子對儒學的深心關懷。

　　　　　Confucians in the Sung Dynasty had intense study on the Buddhism and Taoism, and so they had profound conversation about Buddhology. Chu Shi, among scholars in that period who studied philosophies, was the master of the classic school. However, his notion of Buddhology did not correspond to the Buddhism beliefs. According to the classic school, the quality of nature is within reason. However, from the Buddhist's point of view, wisdom is nothing to do with reason. A Buddhist's practice is to eliminate the attachment to external form and to gain an insight into the quality of emptiness. That was the reason Chu Shi misunderstood "the emptiness of nature" as "nonexistence of the natural law.". Chu Shi had concentrated on the study and practice of Confucianism for life. He took Confucianism as practical and Buddhism as vacuous. As a model of Confucians who devoted his knowledge to benefit people, Chu Shi's notion was adequate to support his beliefs.