The four theistic proofs of Monologion are based on the categories of being per se and being per aliud. This article analyses them through a comparative approach. The categories of per se and per aliud are compared with the categories of substance (ti) and function (yong) as touched on the first chapter of the Rectifying Ignorance (正蒙 Zhengmeng) of Zhang Zai (1020–1077), an exponent of neo-Confucianism. In fact, the two pairs of categories explain the relationship between an absolute, the supreme (...) nature (summum) or the Great Void (太虚 taixu) and the sensible world. Through the comparison, this article highlights the fundamental function of being per aliud in the rational knowledge of the supreme nature that exists per se and provides new insights into the process of derivation of being per aliud from the being per se.Contribution: This article, through the comparison with the Chinese philosophical tradition, intends to offer a new perspective on the understanding of the Anselmian categories of being per se and being per aliud. (shrink)