Nagarjuna was an Indian Buddhist philosopher, active by tradition around the second century CE, who founded the Madhyamaka or 'Middle Way' school and gave systematic argument to the Mahayana idea of emptiness: the claim that nothing possesses an independent, self-standing nature of its own. His Fundamental Verses on the Middle Way became one of the most influential and most argued-over texts in the history of Asian philosophy.
Nagarjuna taught that nothing in the world has a fixed nature of its own. His critics drew the obvious conclusion. If nothing is truly real on its own, then nothing is real at all, and this monk believed in emptiness the way others believe in God. He answered that they had read him exactly backwards. A thing with a locked, permanent essence could never change, never grow, never be set free. Only because things are hollow at the core, dependent and open, can anything happen at all. Emptiness, he said, was not a void behind the world. It was the reason there could be a world.