Nagarjunian-Yogacarian Modal Logic versus Aristotelian Modal Logic

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 (pi epsilon rho iota epsilon rho mu eta nu epsilon iota alpha sigma, De Interpretatione) has introduced some modal-logical relationships which correspond to T. In this logic, it is supposed that there are contingent events. The Nagarjunian treatise Isvara-kartrtva-nirakrtih-vi?noh-ekakartrtva-nirakarana 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 Nagarjunian approach was inherited by the Yogacarins who developed, first, the doctrine of causality of all real entities (arthakriyatva) and, second, the doctrine of momentariness of all real entities (k?anikavada). Both doctrines were a philosophical ground of the Yogacarins for the logical determinism. Hence, Aristotle implicitly used the logic T in his modal reasoning. The Madhyamaka and Yogacara schools implicitly used the logic K = in their modal reasoning.

Automated summary

There are two different modal logics: logic T assumes contingency and logic K = assumes logical determinism. Aristotle and Nagarjuna used these logics in their modal reasoning, with Aristotle implicitly using logic T and Nagarjuna using logic K =.