Abstract
The year 1964 witnessed the polemics on "one divides into two" and "two combine into one" conducted in China's theoretical circles. Due to the sabotage of the "theoretical authority" and people like Guan Feng, this academic discussion was turned into a political mass criticism of the latter. During the Cultural Revolution, Lin Biao and the "gang of four" subjected comrades who advocated the theory of "two combine into one" or endorsed some of its viewpoints to brutal political persecution. Criticism of the theory was a political frame-up. However, I think we should conduct realistic discussion and evaluation of it again as a theoretical issue, in the spirit of fostering democracy and "letting a hundred schools of thought contend." To my way of thinking, "two combine into one" is neither a metaphysical proposition nor a comprehensive generalization of the law of the unity of opposites. It is the generalization of the identity of contradiction in its first meaning