This article demonstrates that Lacanian thought on One is narrow and does not completely cover the whole reality of One. A better understanding of One and Two could be facilitated by using the representation ‘#’, which can explain both disjunction and unity in language and thought. In addition, it presents some possibilities in abstract thinking. The first section of the paper considers Lacan’s doctrine on One and difference. The following section elaborates on the defect of this doctrine, focusing especially on (...) its onesided apprehension, and introducing the derivation of the representation ‘#’. In the last section, the representation ‘#’ and its usage are briefly explained. (shrink)