One big line, that first

To understand the whole field, start with one line. Shruti (sruti), that which was heard, is the name of the Veda, held to be eternal and apauruseya, the highest authority. Smriti (smrti), that which was remembered, is the tradition made by human hands, which holds and puts to use what shruti gave. The schools that accept the Veda are astika (astika); those that do not are nastika (nastika).

Inside the Veda

The Veda is one light, divided into four collections: the Rigveda, the Samaveda, the Yajurveda (in one Krishna and one Shukla recension), and the Atharvaveda. These were kept alive in shakhas, branches, most of which are now lost. Each Veda has four layers, and they run nearly in order of time: Samhita (sukta, mantra), Brahmana (the prose of ritual), Aranyaka (the forest texts), and Upanishad (Vedanta, the end of the Veda). The journey from rite up to liberating knowledge is completed within shruti itself.

The spread of smriti

Smriti is large and open. The six Vedangas and the Kalpa Sutras (Shrauta, Grihya, Dharma, Shulba). Itihasa, meaning the Ramayana and the Mahabharata, with the Bhagavad Gita seated inside that same Mahabharata. The Puranas, eighteen major and eighteen minor, divided among Vaishnava, Shaiva, and Shakta. The codes of the Dharmashastra, Manu and Yajnavalkya. The root sutras of the six darshanas: Nyaya, Vaisheshika, Samkhya, Yoga, Mimamsa, and Vedanta. And the later vernacular bhakti: the Tamil Divya Prabandham, the Ramcharitmanas, the Hanuman Chalisa.

The parallel stream

One stream flows alongside: the Agamas and Tantras, which the tradition sets beside the Vedic Nigama under the name Agama. The living liturgy of the temple comes from here: the Shaiva Agamas, the Vaishnava Samhitas (Pancharatra, Vaikhanasa), and the Shakta Tantras. Two Vedic pages on this site connect to this world of worship, though they are themselves shruti, limbs of the Veda: Sri Rudram and Chamakam and Purusha Sukta.

Separate canons

Some canons stand apart, outside this house. The Buddhist: the Tripitaka and the Mahayana sutras. The Jain: the Agamas. And the Sikh: the Guru Granth Sahib, compiled in 1604.

What makes it one system

Three relationships turn this pile into a system. First, that four-layer build inside the Veda, from Samhita to Upanishad. Second, the Prasthana-trayi, the Upanishads, the Brahma Sutra, and the Gita, the shared threefold base on which every school of Vedanta writes its commentary, and the very bridge that ties the Gita of smriti to the authority of shruti. Third, the distinction of Nigama and Agama, by which the temple’s living worship runs on the Agama while the Veda still stands above. When all of this was composed in time, the next page takes up: The canon in time.