Nagarjuna is a great philosopher, one of the greatest of the world. Only a few people in the world, very few, have that quality of penetration that Nagarjuna has. So, his way of talking is very philosophical, logical, absolutely logical.

Nagarjuna is one of the greatest disciples of Buddha, and one of the most penetrating intellects ever. Only very few people — once in a while, a Socrates, a Shankara — can be compared with Nagarjuna. He was very, very intelligent. The uttermost that the intellect can do is to commit suicide; the greatest thing, the greatest crescendo that can come to the intellect is to go beyond itself — that’s what Nagarjuna has done. He has passed through all the realms of intellect, and beyond.
– The Heart Sutra, Chapter #2

Nagarjuna was one of the greatest mystics India has given birth to. He realized his infinite being, the world dissolved. Then followers came, and followers are always carbon copies, bound to be unless they try to penetrate the reality themselves and don’t take their Master’s word on trust.

The Master’s word simply inspires, provokes, helps, but it should not be taken on trust, otherwise it will become a philosophy. YOU have to realize it. And when YOU realize, only then can you say, “Yes, the Master was true.”
– Hsin Hsin Ming: The Book of Nothing, Chapter #3

There has been a great man in India, a very rare being: men like him you can count on your fingers. His name was Nagarjuna. He has contradicted everything. He has debated against everything. He has criticized all theories. And people were puzzled. They would ask: Okay, whatsoever you say is okay, but what is YOUR standpoint? He would say: I don’t have any standpoint. I am here just to destroy theories, I don’t have a theory to replace them with. Whatsoever is your theory — Come! And I will criticize it and destroy it. But don’t ask for a substitute because I have none. You become empty, that’s perfect, there is no need to do anything.
– Tao: The Three Treasures, Vol 3, Chapter #5

Nagarjuna was one of the great masters India has produced — of the caliber of Buddha and Mahavir and Krishna. And Nagarjuna was a rare genius. Really, on the intellectual level there is no comparison in the whole world; such a keen and penetrating intellect rarely happens.
– Vigyan Bhairav Tantra, Vol 1, Chapter #16

The chronological time is arbitrary. In the West Zeno proved it long before. In the East Nagarjuna proved it so deeply that he has never been refuted. In fact Zeno and Nagarjuna, two persons, have remained irrefutable. Nobody can refute them; their arguments are so deep and absolute. Zeno and Nagarjuna say that the whole concept of time, chronological time, is absurd.
– Yoga: The Alpha and the Omega, Vol 9, Chapter #7

Nagarjuna, a disciple of Buddha, has written a shastra called, MOOL MADHYAMIC KARIKA. This book has no equal in the world. Naturally, for it is next to impossible to find, again, a person like Nagarjuna. He has proved in this book that nothing exists. Neither you nor I, nor the mundane world — nothing is.
– The Way of Tao, Volume 2, Chapter #9

Nagarjuna’s MULA MADHYAMIKA KARIKA. I don’t like Nagarjuna very much; he is too much of a philosopher, and I am anti-philosophic. But his MULA MADHYAMIKA KARIKA, his KARIKAS for short…. MULA MADHYAMIKA KARIKA means the essence of the path of the middle — the essential middle path. In his KARIKAS he has reached the profoundest depths of which words are capable. I have never spoken on it. If you want to speak on the essential, the best way is not to speak at all, just to be silent. But the book is tremendously beautiful.
– Books I Have Loved, Chapter #4