There are two different modal logics: the logic T assuming contingency and the logic K = assuming logical determinism. In the paper, I show that the Aristotelian treatise On Interpretation (Περί ερμηνείας, De Interpretatione) has introduced some modal-logical relationships which correspond to T. In this logic, it is supposed that there are contingent events. The Nāgārjunian treatise Īśvara-kartṛtva-nirākṛtiḥ-viṣṇoḥ-ekakartṛtva-nirākaraṇa has introduced some modal-logical relationships which correspond to K =. In this logic, it is supposed that there is a logical determinism: each event happens necessarily (siddha) or it does not happen necessarily (asiddha). The Nāgārjunian approach was inherited by the Yogācārins who developed, first, the doctrine of causality of all real entities (arthakriyātva) and, second, the doctrine of momentariness of all real entities (kṣaṇikavāda). Both doctrines were a philosophical ground of the Yogācārins for the logical determinism. Hence, Aristotle implicitly used the logic T in his modal reasoning. The Madhyamaka and Yogācāra schools implicitly used the logic K = in their modal reasoning.

有两种不同的模态逻辑：假定偶然性的逻辑T和假定逻辑确定性的逻辑K =。在本文中，我表明亚里士多德的《解释论》（De Interpretatione）引入了一些与T对应的模态逻辑关系。按照这种逻辑，假定存在偶发事件。Nāgārjunian的论着Īśvara-kartṛtva-nirākṛtiḥ-viṣṇoḥ-ekakartṛtva-nirkarakaraṇa引入了一些与K =对应的模态逻辑关系。按照这种逻辑，假定存在逻辑确定性：每个事件必然发生（siddha），或者不一定会发生（asiddha）。纳加尔努尼亚人的方法是由尤加卡林人继承的，他首先发展了所有真实实体的因果关系学说（arthakriyātva），其次发展了所有真实实体的瞬时性学说（kṣaṇikavāda）。两种学说都是约加卡林人关于逻辑决定论的哲学基础。因此，亚里士多德在其情态推理中暗含了逻辑T。Madhyamaka和Yogācāra学派在模态推理中暗含了逻辑K =。