The Fundamental Wisdom of the Middle Way - Nagarjuna [trans - J. Garfield] (epub mobi)

from Wikipedia:

Nāgārjuna (Devanagari: नागार्जुन, Telugu: నాగార్జున, Tibetan: ཀླུ་སྒྲུབ་ klu sgrub, Chinese: 龍樹, Japanese: 龍樹 Ryūju, Sinhala නාගර්ජුන) (ca. 150–250 CE) is widely considered one of the most important Buddhist philosophers after the historical Buddha. Along with his disciple Āryadeva, he is credited with founding the Madhyamaka school of Mahāyāna Buddhism. Nāgārjuna is also credited with developing the philosophy of the Prajñāpāramitā Sūtras and, in some sources, with having revealed these scriptures in the world, having recovered them from the nāgas (dragons). Furthermore, he is traditionally supposed to have written several treatises on rasayana alchemy as well as serving a term as the head of Nālandā University.

The Mūlamadhyamakakārikā[1] (Devanagari: मूलमध्यमककारिका), or Fundamental Verses on the Middle Way, is a key text of the Madhyamaka-school, written by Nagarjuna, one of the most important Buddhist philosophers.

The Mūlamadhyamakakārikā is Nagarjuna's best known work. It is
[N]ot only a grand commentary on the Buddha's discourse to Kaccayana,[2] the only discourse cited by name, but also a detailed and careful analysis of most of the important discourses included in the Nikayas and the agamas, especially those of the Atthakavagga of the Sutta-nipata.

In this work,
Utilizing the Buddha's theory of "dependent arising"(pratitya-samutpada), Nagarjuna demonstrated the futility of [...] metaphysical speculations. His method of dealing with such metaphysics is referred to as "middle way" (madhyama pratipad). It is the middle way that avoided the substantialism of the Sarvastivadins as well as the nominalism of the Sautrantikas.

Nagarjuna insisted that...
[A]ll experienced phenomena are empty (sunya). This did not mean that they are not experienced and, therefore, non-existent; only that they are devoid of a permanent and eternal substance (svabhava). Since they are experienced, they are not mere names (prajnapti).