"So Kṛṣṇa consciousness means to have all kinds of knowledge. Not that we Kṛṣṇa conscious people are being carried away by some sentiment. No. We have got philosophy, science, theology, ethics, morality, everything—everything that is required to be known in human form of life. So Kṛṣṇa says that 'I'll speak to you all about knowledge.' So this is Kṛṣṇa consciousness. A Kṛṣṇa consciousness, a Kṛṣṇa conscious person should not be fool. If he is required to explain how these universal planets are floating, how this human body is rotating, how many species of life, how they are being evolved... These are all scientific knowledge. Physics, botanics, chemistry, astronomy, everything. Therefore Kṛṣṇa says, yaj jñātvā, if you understand this knowledge, Kṛṣṇa consciousness, then you'll have nothing to know. That means you'll have complete knowledge. We are hankering after knowledge, but if we are in knowledge of Kṛṣṇa consciousness, if we know Kṛṣṇa, then all knowledge is included.
So tac-chakti viṣaya vivikta-svarūpa viṣayakaṁ jñānam. You'll have full knowledge about the constitutional position of yourself, this material world, the spiritual world, God, our interrelationship, time, space, everything. There are many things to be known. But the principal thing is that the God, the living entities, time, work, and this material energy. These five things are to be known. You cannot deny that 'There is no God.' God is controller, supreme controller. You cannot say that you are not controlled. There is controller. Just like in the state, you cannot say there is no controller. There is controller. In every street, in every house, there is control, government control. Suppose this store, here is also government control. You have to build store like this, you cannot live. If it is residential house, 'The fire arrangement should be like this.' There is control. Even you walk in the street, you drive your car, there is control: 'Keep to the right.' You cannot cross where there is written 'Stop.' You have to stop.
So in every way, you are under control. So there is a controller. And the supreme controller is Kṛṣṇa. There is one controller over another controller. If you go on searching out who is the ultimate controller, then you'll find Kṛṣṇa. Sarva-kāraṇa-kāraṇam (Bs. 5.1). The Brahma-saṁhitā affirms, īśvaraḥ paramaḥ, the supreme controller is Kṛṣṇa. Īśvaraḥ paramaḥ kṛṣṇaḥ (Bs. 5.1). Īśvaraḥ means controller. So we have to get knowledge of this controller, how He is controlling. So jñānaṁ vijñānaṁ te sahitam. Not only to know the controller, but to know how He is controlling, how many energies the controller has got and how He is one controlling—that is vijñānam. So jñānaṁ vijñānaṁ te nate tubhyāṁ prapannāya aśeṣataḥ.
Now this knowledge can be understood by a person who has made relationship with Kṛṣṇa and is a surrendered soul. Without being surrendered, it is very difficult to understand the controller and the energies, how He is controlling everything. Tubhyāṁ prapannāya aśeṣataḥ samagreṇa upadekṣyāmi. This is the condition. You will find in the later chapters that Kṛṣṇa says, nāhaṁ prakāśaḥ sarvasya (BG 7.25). Just like if you enter into any educational institution, if you don't surrender yourself to the rules and regulation of the institution, how you can get advantage of the knowledge imparted by the institution? Everywhere, wherever you want to receive something, you have to be controlled or you have to be surrendered to the rules and regulation. Just like in our class we are imparting some lessons from the Bhagavad-gītā, and if you do not follow the rules and regulations of this class, it is not possible to receive the knowledge. Similarly, the full knowledge of the controller and the process of controlling can be understood when one is surrendered like Arjuna to Kṛṣṇa. Unless one is surrendered soul, it is not possible."
(Srila Prabhupada Lecture, San Francisco, September 11, 1968)