Shloka 37
Brahma-vidyā: Satya–Tapas and the Enumeration of Tattvas
Arjuna–Vāsudeva framed dialogue
चातुर्विद्यं तथा वर्णाश्चातुराश्रमिकान् पृथक् । धर्ममेकं चतुष्पादं नित्यमाहुर्मनीषिण:
cāturvidyaṃ tathā varṇāś cāturāśramikān pṛthak | dharmam ekaṃ catuṣpādaṃ nityam āhur manīṣiṇaḥ ||
我也将分别说明：为各个种姓（varṇa）与四住期（āśrama）所规定的四种学业。智者恒常宣说：法唯有一，而立于四支（四种支撑）之上。
वायुदेव उवाच
Educational Q&A
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’.