Vijñāna means... Vi means specific. It is a specific knowledge, and it has to be understood by a specific process. Generally, we understand, we acquire knowledge by direct perception, experimental knowledge, direct perception. But bhagavad-vijñāna, the science of God, is so extensive and so intricate that it is not possible to apply our imperfect senses to understand the science of God. Then we have to understand with our senses. Otherwise what is the meaning of understanding? Hear. Therefore these senses, when they will be purified, then we can understand. Just like a man cannot see due to some cataract complication, but if the cataract portion is surgically operated, he can see also. Treatment. Similarly, it is said in the śāstras that ataḥ śrī-kṛṣṇa-nāmādi na bhaved grāhyam indriyaiḥ (CC Madhya 17.136). Our senses are very imperfect. That we can understand. For example, we are daily seeing the sun globe, but our experience is just like a disc because my eyes cannot see things placed in long distance, neither can see which is very near. Just like the eyelid is just attached to the eye, but I cannot see. This is imperfect. Neither we can see very close, neither we can see very long distance point, neither we can see in darkness. There are so many conditions. If those conditions are fulfilled, then our senses can act. Therefore it is to be understood that our senses are imperfect.
Therefore Bhāgavata says ataḥ, therefore, śrī-kṛṣṇa-nāmādi, Śrī Kṛṣṇa, the Supreme Personality of Godhead, nāmādi... Nāma means His name, His holy name, ādi, that is the beginning. To understand Kṛṣṇa is to begin chanting His name, nāma. Nāmādi. Ādi means in the beginning. Therefore we recommend the students to chant Hare Kṛṣṇa. Ataḥ śrī-kṛṣṇa-nāmādi. Nāma means after you understand or realize nāma, then you'll understand His qualities, transcendental qualities. When, in the Vedic scripture, when it is said that the Absolute Truth is nirguṇa... Nirguṇa means, guṇa means quality, and nir means negative. And nir, nir, na arthe. Nir also used to ascertain. So nirguṇa can be used in two senses. The first sense is negative, "no guṇa, no quality," and the second is "it is difficult to ascertain."