The One Divides into Two (一分为二) controversy was an ideological debate about the nature of contradiction that took place in China in 1964.
The philosopher Yang Xianzhen originated the idea of "Two Unites into One", which he said was the primary law of dialectics.
Ai Siqi wrote the original attack on Yang, and was joined by Mao himself.
This phrase is derived from the formulation given by Vladimir Lenin in his Philosophical Notebooks; "The splitting of a single whole and the cognition of its contradictory parts ... is the essence ... of dialectics.
[citation needed] Alain Badiou, during his Maoist phase, would use the principle of One Divides into Two to criticize the philosophy of Gilles Deleuze.