As the school of logic whose main stream was Moism flowered but bore no fruit, in China all the comprehensive systems of logic were foreign imports. The precursor was the yin-ming (Buddhistic logic) of T'ang; the successor, the ming-hsüeh (Western logic) of Ming and Ch'ing. This article aims to evaluate in an objective manner without allegiance to any one school the Buddhistic yin-ming in a modern context. Of its four sections, the first is an introduction which offers a brief explanation of the significance of yin-ming in the history of Chinese culture and leads to the necessity of inquiring into the reliablity of this logical system. In the next two sections the writer employs Western tranditional and symbolic logic to analyse and discuss strictly the syllogistic Structure of Buddhistic logic and the application of its inferences, arriving finally at the conclusion of the "duality of yin-ming", i.e., certainty in structure, but probability in application. In the last section he reviews the basic genius of this system.