The cleared mind through regulated living alone can perceive the eternal soul and its relationship with Krishna.Listen — Srila Prabhupada Uvaca
Bhagavad-gītā 13.5 — August 13, 1973, Paris 730813BG-PARIS [41:01 Minutes] Bg-13.05_730813BG-PARIS Pradyumna: Oṁ namo bhagavate vāsudevāya. Oṁ namo bhagavate vāsudevāya. Oṁ namo bhagavate vāsudevāya. [leads chanting of verse] [devotees repeat] ṛṣibhir bahudhā gītaṁ chandobhir vividhaiḥ pṛthak brahma-sūtra-padaiś caiva hetumadbhir viniścitaiḥ [Bg. 13.5] ṛṣibhiḥ—by the wise sages; bahudhā—in many ways; gītām—described; chandobhiḥ—Vedic hymns; vividhaiḥ—in various; pṛthak—variously; brahma-sūtra—the Vedānta; padaiḥ—aphorism; ca—also; eva—certainly; hetumadbhiḥ—with cause and effect; viniścitaiḥ—ascertain.
[02:03] Translation: "That knowledge of the field of activities and of the knower of activities is described by various sages in various Vedic writings, especially in the Vedānta-sūtra, and is presented with all reasoning as to cause and effect." Prabhupāda: So about the soul and Supersoul, ṛṣibhiḥ, great sages, saintly persons, they have also discussed. Just like in the present age also, we are different parties, the impersonalist and the personalist. Śaṅkara-sampradāya, they ascertain the Absolute Truth as impersonal, nirviśeṣa, and the Buddhists, they ascertain, "The Absolute Truth is zero." We are struggling—nirviśeṣa-śūnyavādi. We are struggling against these nirviśeṣa-śūnyavādi, voidists and impersonalists. So it is not now new.
From time immemorial there are different views. But Kṛṣṇa refers herewith that brahma-sūtra-padaiḥ hetumadbhir viniścitaṁ. Others... There are many other books of knowledge, they are not very reasonable.
That is dogmatic. But hetumadbhiḥ, if we accept with our logic and sense, that is first-class book which gives us information of the ātmā, Paramātmā. Therefore, in the Caitanya-caritāmṛta the author says, caitanyera dayāra kathā karaha vicāra vicāra karile citte pābe camatkāra The author says that "You kindly put your consideration and judgment about the mercy of Lord Caitanya Mahāprabhu. And if you consider with logic and reason," vicāra karile pābe citte camatkāra, "you'll feel that these are wonderful things." So we haven't got to accept anything blindly.
The Brahma-sūtra, or Vedānta-sūtra, is called nyāya-prasthāna. There are three different processes for understanding the Absolute Truth: nyāya-prasthāna, śruti-prasthāna, smṛti-prasthāna. Brahma-sūtra is nyāya-prasthāna. Nyāya-prasthāna means everything, all the sūtras and codes, are there with full reasoning.
Hetumadbhir viniścita. And whatever Brahma-sūtra says, that is viniścita, means ascertained. There is no doubt. Just like Brahma-sūtra says, athāto brahma jijñāsā.
Brahma-sūtra says, "Now it is the time for inquiring about the Absolute Truth." "Now" means in this life, human form of life, or... Just like in Europe and America, it is the time now to inquire of the Absolute Truth because materially they are advanced. They have seen all material advancement. The scientists are now perplexed that "How we shall maintain ourselves? Because we have nothing to give anymore.