Answer:
2. Catuṣkoṭi
Step-by-step explanation:
Nagarjuna was an Indian thinker and a Buddhist philosopher who founded the Madhyamaka school of Mahayana Buddhism. He was born to a family of the Brahmin class in Hinduism but later on, he became a Buddhist.
He relied on the logical argument called "Catuṣkoṭi," which tackled on 4 corners or circles:
- "A"
- "not A"
- "A and not A"
- "not A and not not A"
It became a way of learning and investigating. It also had a huge impact on the Buddhist logic.