Set on the battlefield of Kurukshetra, the Gita answers Arjuna's crisis of conscience with a synthesis of Karma, Bhakti, and Jnana Yoga — action performed without attachment to its fruit, devotion to the divine, and knowledge of the eternal Self.

• Ch. 2 — Sankhya Yoga: the immortality of the soul, and the discipline of steady wisdom.
• Ch. 6 — Dhyana Yoga: the practice and posture of meditation.
• Ch. 12 — Bhakti Yoga: the path of loving devotion.
• Ch. 18 — Moksha Sannyasa Yoga: the Gita's closing synthesis of all its paths.

A collection of philosophical dialogues appended to the Vedas, exploring Brahman (ultimate reality) and Atman (the individual self), and the recognition — tat tvam asi, 'that thou art' — that the two are not separate.

• Isha Upanishad — renunciation within, not withdrawal from, the world.
• Katha Upanishad — Nachiketa's dialogue with Yama on death and the eternal Self.
• Mandukya Upanishad — the syllable Om and the four states of consciousness.
• Chandogya Upanishad — the teaching of tat tvam asi.

A terse, systematic set of aphorisms reconciling the teachings of the Upanishads into a single coherent philosophy — the foundational text for every later Vedanta commentary, including Shankaracharya's Advaita reading.

• Samanvaya Adhyaya — establishing Brahman as the source of all scripture's teaching.
• Avirodha Adhyaya — reconciling apparent contradictions across the Upanishads.
• Sadhana Adhyaya — the means to liberating knowledge.
• Phala Adhyaya — the fruit of realization.

The foundational text of classical yoga, defining yoga as citta-vritti-nirodha — the stilling of the fluctuations of the mind — and laying out the eight limbs (Ashtanga) from ethical restraint to absorption.

• Samadhi Pada — the nature and goal of yoga.
• Sadhana Pada — the eight limbs, including the yamas and niyamas.
• Vibhuti Pada — the powers (siddhis) that may arise in practice.
• Kaivalya Pada — liberation and final aloneness of pure consciousness.

The oldest layer of Sanatana Dharma's scripture — hymns, chants, ritual formulas and philosophical speculation, compiled over centuries and transmitted with extraordinary oral precision long before being written down.

• Rigveda — hymns to the deities, including the Nasadiya Sukta on creation.
• Samaveda — melodies for chanting Rigvedic hymns in ritual.
• Yajurveda — ritual formulas for sacrificial ceremony.
• Atharvaveda — spells, charms, and everyday wisdom, distinct in character from the other three.