「氣」這個概念，在中國人的思想中，非但凝聚著先哲對自然宇宙所以然的理解，更蘊含有先哲們的人道情懷，深刻的反應終極人文關懷。為能確切地了解中國文化的精髓，以氣為範疇的氣論就成為必須研究的關鍵課題，然而每一次外域文化的傳入，會掀起中國本土文化的衝擊，當明末之際，西方傳教士湧入中國，帶來了數學、天文、地理、醫學、機械等西方知識，中國傳統文化在各方面的相互參照下，經歷了前所未有的碰撞與批判，當西方文化特別是科學思想的輸入後，對中國傳統氣的哲學產生了什麼轉化？生逢此嬗變過程的方以智是重要的代表學者之一，他參照西學，對中傳統氣進行初步的審視與批判，促使中國傳統氣論有著創造性的轉化。氣火一體思想的提出不僅代表著他個人的自然哲學特質，從中亦可窺見明法之際氣之哲學的展開，所帶動哲學思潮的轉化。

In Chinese philosophy, the concept of “qi” contains not only the ancient philosophers’ understanding of the universe as it is but also their humanistic feelings, which reflect their ultimate humanistic concerns. To correctly understand the essence of Chinese culture, it is critical for one to study the theory of Qi. Yet whenever any foreign culture is brought in, Chinese culture is seriously impacted. In the end of the Ming Dynasty, missionaries form the West poured into China, bringing with them Western knowledge like mathematics, astronomy, geography, medicine and mechanics. Being compared with Western knowledge in every respect, traditional Chinese culture encountered unprecedented clashes and criticism. When Western culture, especially scientific thought, was brought in, what kind of transformation did the traditional Chinese philosophy of qi go through? Experiencing and witnessing such a change, Feng, Yi Zhi was one of the important scholars of the time. He referred to western knowledge and made a preliminary review and critique about the traditional Chinese theory of qi, putting the theory through a creative transformation. The proposal of the concept of “unity of Qi and fire” not only represented the nature of his own natural philosophy but also reveled the transformation of the philosophical thoughts that was promoted by the development of the philosophy of qi in the late Ming and early Qing Dynasties.