Brahma-vidyā: Satya–Tapas and the Enumeration of Tattvas
Arjuna–Vāsudeva framed dialogue
अतत्तत्त्वानि वक्ष्यामि याथातथ्येन हेतुना । विषयस्थानि सर्वाणि वर्तमानानि भागश:,अब मैं यथार्थ युक्तिके द्वारा पदार्थोमें विभागपूर्वक रहनेवाले सम्पूर्ण तत्त्वोंका वर्णन करता हूँ
atattattvāni vakṣyāmi yāthātathyena hetunā | viṣayasthāni sarvāṇi vartamānāni bhāgaśaḥ ||
Vāyu said: “I shall now explain the principles as they truly are, supported by sound reasoning—showing how all the factors that operate in the fields of experience exist in distinct divisions.”
वायुदेव उवाच
That true understanding should be presented “as it is” (yāthātathya), grounded in reason (hetu), by distinguishing the operative principles (tattvas) that structure experience into clear categories (bhāgaśaḥ).
Vāyu-deva begins a didactic exposition: he announces that he will systematically describe the fundamental principles that function within the domains of experience, setting up a structured philosophical explanation.