From the traditional point of view of the Indo-Tibetan form of Mahayana (Skt. Mahāyāna) Buddhism, Buddha himself taught four major tenet systems (grub-mtha’, Skt. siddhānta) to suit the dispositions and capacities of different disciples. Hinayana (Skt. Hīnayāna) had eighteen schools and within one of them, Sarvastivada (Thams-cad yod-par smra-ba), two of the tenet systems emerged: Vaibhashika (Bye-brag smra-ba) and Sautrantika (mDo-sde-pa). The other two appeared within Mahayana: Chittamatra (Sems-tsam-pa) and Madhyamaka (dBu-ma-pa). Other names for Chittamatra (Skt. Cittamātra) are Yogachara (rNal-’byor spyod-pa) and Vijnanavada (rNam-par shes-pa tsam-du smra-ba). Although other Hinayana schools, for instance Theravada (gNas-brtan smra-ba, Skt. Sthaviravāda), have their own distinctive set of assertions, they are not counted among the tenet systems.
Various Tibetan masters have identified and named differently subdivisions within each of the four traditional Indian tenet systems. There is little evidence, however, that these subdivisions existed in India. The most important of them is the subdivision of Madhyamaka (Skt. Mādhyamaka) into Svatantrika-Madhyamaka (dBu-ma rang-rgyud-pa) and Prasangika-Madhyamaka (dBu-ma thal-’gyur-pa). Also significant, according to Gelug, is the division within Svatantrika-Madhyamaka between Yogachara-Svatantrika (rNal-byor spyod-pa’i dbu-ma rang-rgyud-pa) and Sautrantika-Svatantrika (mDo-sde-pa’i dbu-ma rang-rgyud-pa).
From a historical point of view, various Indian masters specialized in and taught these systems as separate Buddhist traditions. The fact that some of them were transmitted to China as individual schools corroborates this fact.
In the Indian Mahayana Buddhist monasteries, such as Nalanda (Skt. Nālandā), monks studied all four traditions. The Tibetans have followed this custom, with different subjects and texts taught from the points of view of different tenet systems.
The Four Major Tenet Systems
Tibetans study Vaibhashika (Skt. Vaibhāṣika) in the context of special topics of knowledge (chos mgon-pa, Skt. abhidharma), specifically the lower system of abhidharma (mngon-pa ‘og-ma), as formulated by Vasubandhu (dByigs-gnyen).
- Vasubandhu wrote A Treasure House of Special Topics of Knowledge (Chos mngon-pa’i mdzod, Skt. Abhidharmakośa).
They study Sautrantika (Skt. Sautrāntika) in the context of valid cognition (tshad-ma, Skt. pramāṇa), as formulated by Dignaga (Phyogs-kyi glangs-pa) and Dharmakirti (Chos-kyi grags-pa).
- Dignaga (Skt. Dignāga) wrote A Compendium of Validly Cognizing Minds (Tshad-ma kun-las btus-pa, Skt. Pramāṇasamuccaya).
- Dharmakirti (Skt. Dharmakīrti) wrote A Commentary to (Dignaga’s “Compendium of) Validly Cognizing Minds” (Tshad-ma rnam-’grel, Skt. Pramāṇavārttika).
Tibetans study Chittamatra in the context of the higher system of abhidharma (mngon-pa gong-ma), as formulated by Asanga (Thogs-med). They supplement this with further aspects of valid cognition in Dharmakirti’s Commentary to (Dignaga’s “Compendium of) Validly Cognizing Minds.”
- Asanga (Skt. Asaṅga) wrote An Anthology of Special Topics of Knowledge (mNgon-pa chos kun-las btus-pa, Skt. Abhidharmasamuccaya).
They study Madhyamaka in general as presented in the works of Nagarjuna (Klu-sgrub).
- Nagarjuna wrote Root Verses on the Middle Way, Called Discriminating Awareness (dBu-ma rtsa-ba shes-rab, Skt. Prajñānāma-Mūlamadhyamakakārikā), and many other texts.
The Two Divisions of Madhyamaka
Tibetans study Svatantrika-Madhyamaka in general in the context of far-reaching discriminating awareness (sher-phyin, Skt. prajñāpāramitā, perfection of wisdom), as formulated by Maitreya (Byams-pa).
- Maitreya wrote A Filigree of Realizations (mNgon-rtogs rgyan, Skt. Abhisamayālaṃkāra).
They study Prasangika-Madhyamaka through the works of Chandrakirti (Zla-ba grags-pa), Aryadeva (’Phags-pa lha), Shantideva (Zhi-ba lha), and Buddhapalita (Sang-rgyas bskyangs).
- Chandrakirti (Skt. Candrakīrti) wrote Engaging in the Middle Way (dBu-ma-la ’jug-pa, Skt. Madhyamakāvatāra).
- Aryadeva (Skt. Āryadeva) wrote Four Hundred Verse Treatise (bZhi-brgya-pa, Skt. Catuḥśataka).
- Shantideva wrote Engaging in Bodhisattva Behavior (sPyod-’jug, Skt. Bodhisattvacaryāvatāra).
- Buddhapalita (Skt. Buddhapālita) wrote A Commentary to (Nagarjuna’s) “Root Verses on the Middle Way, Called Discriminating Awareness” (rTsa-ba shes-rab-gyi ’grel-ba, Skt. Mūlamadhyamakavṛtti).
The Two Divisions of Svatantrika-Madhyamaka
Tibetans study Yogachara-Svatantrika through the works of Shantarakshita (Zhi-ba ’tsho), who first brought Indian Buddhism to Tibet, and his disciples Kamalashila (Ka-ma-la shi-la), who defeated the Chinese monk Hoshang at the Samye debate, and Haribhadra (Seng-ge bzang-po).
- Shantarakshita (Skt. Śāntarakṣita) wrote A Filigree of the Middle Way (dBu-ma rgyan, Skt. Madhyamakālaṃkāra) and A Compendium of Principles (De-kho-na-nyid-kyi bsdud-pa, Skt. Tattvasaṃgraha).
- Kamalashila (Skt. Kamalāśīla) wrote Stages of Meditation (sGom-rim, Skt. Bhāvanākrama) and Illumination for the Middle Way (dBu-ma snang-ba, Skt. Madhyamakāloka).
- Haribhadra wrote A Commentary (to Maitreya’s “Filigree of Realizations”), Clarifying the Meaning (’Grel-ba don-gsal, Skt. Sphuṭārthā).
They study Sautrantika-Svatantrika through the works of Bhavaviveka (Bhavya) (Legs-ldan ’byed).
- Bhavaviveka (Skt. Bhāvaviveka) wrote Heart of the Middle Way (dBu-ma’i snying-po, Skt. Madhyamakahṛdaya) and its auto-commentary Blaze of Reasoning (rTog-ge ’bar-ba, Skt. Tarkajvāla).