In June 1997, Ringu Tulku returned to Kagyu Samye Ling in Scotland to resume his commentary on Jamgön Kongtrül Lodro Thaye’s Treasury of Knowledge. These 21 recordings cover all three weeks of these talks and students’ Q&As.

A helpful overview of this encyclopedic work can be found here:

https://www.shambhala.com/treasury-of-knowledge/

Rinpoche starts the first session with a brief overview of all 10 Books. At 00:28:50 in the First Recording, Rinpoche begins to reference the teachings of the Tantrayana/Vajrayana of Book 6. Questions and Answers begin at 00:33:02

The Tantric Path is often referred to as the indestructible way of secret mantra, the essence of which is the indestructible union of:

wisdom (understanding of emptiness) and
skilful means/method (immutable great bliss).

In these teachings, Rinpoche begins to discuss Part 4 of Book6 and the systems that constitute this path, both those of the ancient tantra tradition (A) and of the new tradition (B).

A) In the Nyingma school of Tibetan Buddhism, the tantras are divided into six classes ( རྒྱུད་སྡེ་དྲུག, gyüdé druk):

the three outer classes of tantra (which are common to both the Sarma and Nyingma schools):

1. the Kriya tantra,

2. the Charya tantra and

3. the Yoga tantra.

and

the three inner classes of tantra (which are specific to the Nyingma school):

4. the Mahayoga tantras,

5. the Anuyoga tantras and

6. the Atiyoga tantras.

B) In the Sarma (གསར་མ་) or New Translation Schools of Tibetan Buddhism ie the Kagyü, Sakya, Kadampa and Gelug (which followed the later translations made from the time of the great translator Rinchen Zangpo 958-1055 onwards) four classes of tantra are recognised:

Three outer classes—