The actual practice of yoga, however, is described here. As authoritatively stated in the Śrīmad-Bhāgavatam (12.13.1), dhyānāvasthita-tad-gatena manasā paśyanti yaṁ yoginaḥ: a yogī is one who always meditates on the lotus feet of the Supreme Personality of Godhead. This is also confirmed in the Brahma-saṁhitā (5.38):
premāñjana-cchurita-bhakti-vilocanena
santaḥ sadaiva hṛdayeṣu vilokayanti
yaṁ śyāmasundaram acintya-guṇa-svarūpaṁ
govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
"I worship Govinda, the primeval Lord, who is Śyāmasundara, Kṛṣṇa Himself, with inconceivable innumerable attributes, whom the pure devotees see in their heart of hearts with the eye of devotion tinged with the salve of love." The bhakti-yogī constantly sees Śyāmasundara—beautiful Lord Kṛṣṇa with His blackish bodily hue.
(Srimad Bhagavatam------8:3:27------purport).

No one can understand the transcendental nature of the name, form, quality, and pastimes of Śrī Kṛṣṇa through his materially contaminated senses. Only when one becomes spiritually situated by transcendental service to the Lord are the transcendental name, form, quality, and pastimes of the Lord revealed to him.
This is confirmed in the Brahma-saṁhitā (5.38):
premāñjana-cchurita-bhakti-vilocanena
santaḥ sadaiva hṛdayeṣu vilokayanti
yaṁ śyāmasundaram acintya-guṇa-svarūpaṁ
govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
I worship Govinda, the primeval Lord, who is Śyāmasundara, Kṛṣṇa Himself with innumerable inconceivable attributes, whom the pure devotees see in their heart of hearts with the eye of devotion tinged with the salve of love.
Therefore, the scriptural conclusion is that mundane philosophers like Dr. Radhakrishnan are not qualified to delve into spiritual subjects. The devotees of the Lord alone are eligible to understand Lord Kṛṣṇa; no one else is qualified. As Kṛṣṇa Himself states in the Bhagavad-gītā, bhaktyā mām abhijānāti yāvān yaś cāsmi tattvataḥ: [Bg. 18.55] "One can understand Me as I am, as the Supreme Personality of Godhead, only by devotional service."
(Renunciation through Wisdom).

Śrī Kṛṣṇa’s pastimes in this material world are called prakaṭa-līlā (manifested pastimes), and His pastimes in the spiritual world are called aprakaṭa-līlā (unmanifested pastimes). By “unmanifested” we mean that they are not present before our eyes. It is not that Lord Kṛṣṇa’s pastimes are nonexistent. They are going on exactly as the sun is shining perpetually, but when the sun is present before our eyes, we call it daytime (manifest), and when it is not present, we call it night (unmanifest). Those who are above the jurisdiction of night are always in the spiritual world, where the Lord’s pastimes are constantly manifest to them. As the Brahma-saṁhitā (5.37–38) confirms:
ānanda-cinmaya-rasa-pratibhāvitābhis
tābhir ya eva nija-rūpatayā kalābhiḥ
goloka eva nivasaty akhilātma-bhūto
govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
premāñjana-cchurita-bhakti-vilocanena
santaḥ sadaiva hṛdayeṣu vilokayanti
yaṁ śyāmasundaram acintya-guṇa-svarūpaṁ
govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
“I worship Govinda, the primeval Lord, who resides in His own realm, Goloka, with Rādhā, who resembles His own spiritual figure and who embodies the ecstatic potency [hlādinī]. Their companions are Her confidantes, who embody extensions of Her bodily form and who are imbued and permeated with ever-blissful spiritual rasa. I worship Govinda, the primeval Lord, who is Śyāmasundara, Kṛṣṇa Himself, with inconceivable innumerable attributes, whom the pure devotees see in their heart of hearts with the eye of devotion tinged with the salve of love.”
(Sri Caitanya Caritamrta------2:15:237-------purport).