(Sanskrit) The second century AD Indian Buddhist philosopher who propounded the Madhyamaka philosophy of emptiness. Nagarjuna was the first Buddhist thinker who attempted to systematise Buddhist belief. He wrote extensive commentaries on the the Prajna-Paramita Sutra. He probably lived during the second century CE. Although he founded a Mahayana school, the Madhyamikas, his systematisation was much more important, being used by many Mahayana schools and as being one of the intellectual bases of Vajrayana Buddhism.