The śāstric injunction is, Vedic injunction, that tad-vijñānārthaṁ sa gurum eva abhigacchet (MU 1.2.12). If you want to know transcendental knowledge, tad-vijñāna . . . tad-vijñā . . . it is also vijñāna. Actually, human life is meant for understanding tad-vijñāna. Tad-vijñāna means transcendental knowledge, not material knowledge, bodily. Bodily . . . even a medical practitioner, he does not know, he has no knowledge of the spirit soul. He simply studies the mechanical arrangement of the body. The body's a big machine made by nature. It is called yantra. Actually it is a machine. In the Bhagavad-gītā it is said:
- īśvaraḥ sarva-bhūtānāṁ
- hṛd-deśe 'rjuna tiṣṭhati
- bhrāmayan sarva-bhūtāni
- yantrārūḍhāni māyayā
- (BG 18.61)
Yantrārūḍhāni māyayā. This body is machine. The . . . those who are very much attached to this machine, for them, the yoga system is recommended because . . . one who is very much in the conception of the body, so they have been taught just to concentrate the mind, some practice, some gymnastic, so that mind may be concentrated and he can focus the mind towards Viṣṇu, Lord Viṣṇu. Real purpose is to understand Viṣṇu, the Supreme. So the yoga system is therefore a mechanical arrangement. But the bhakti system is above the machine, above this mechanical arrangement. That is . . . therefore it is called tad-vijñāna. The mechanical understanding is material, and above that, tad-vijñāna.
So tad-vijñānārtham, if you want to understand spiritual knowledge, then you have to approach a guru.