Brahma-vidyā: Satya–Tapas and the Enumeration of Tattvas
Arjuna–Vāsudeva framed dialogue
चातुर्विद्यं तथा वर्णाश्चातुराश्रमिकान् पृथक् । धर्ममेकं चतुष्पादं नित्यमाहुर्मनीषिण:,वैसे ही प्रत्येक वर्ण और आश्रमके लिये पृथक्-पृथक् चार विद्याओंका वर्णन करूँगा। मनीषी विद्वान् चार चरणोंवाले एक धर्मको नित्य बतलाते हैं
cāturvidyaṃ tathā varṇāś cāturāśramikān pṛthak | dharmam ekaṃ catuṣpādaṃ nityam āhur manīṣiṇaḥ ||
Ferner werde ich, jeweils gesondert, die vierfache Lehre darlegen, die für jede Varṇa und für jede der vier Lebensstufen (Āśrama) vorgeschrieben ist. Die Weisen verkünden stets: Es gibt nur eine Dharma, die auf vier Stützen ruht.
वायुदेव उवाच
Dharma is fundamentally one, yet it is understood and practiced through four supports; accordingly, instruction (cāturvidya) and duties are to be explained distinctly for each varṇa and each āśrama so that conduct aligns with one overarching moral order.
Vāyudeva continues a didactic discourse, announcing that he will set out the fourfold learning and the differentiated norms for the social orders and life-stages, while grounding these distinctions in the unity of Dharma described by sages as ‘four-footed’.