"One should have not only theoretical knowledge (jñāna), but practical knowledge (vijñāna). Practical knowledge. Simply understanding that 'I am not this body, I am not body,' then I am doing all nonsense of this body. I am discussing... There are so many societies. They are very seriously discussing Vedānta philosophy and smoking, with wine glass, and very enjoying life. You see. So that sort of jñāna, that sort of knowledge, is not necessary. You see? So jñāna-vijñāna. One should have knowledge perfectly, and it must be demonstrated. Demonstrated in practical field. Yes. But that means one who has actually felt himself that 'I am not this body,' then naturally his bodily necessities will be reduced to the minimum. Will be reduced to the minimum. That is practical. If I am going to increase the demands of my body and I am simply theoretically thinking that 'I am not this body,' oh, that is not required. Jñāna-vijñāna-tṛptātmā.
A man, a person, will be satisfied when there is jñāna, knowledge, and science side by side. Jñāna-vijñāna, practical knowledge. Kūṭastho vijitendriyaḥ. Then he's conquered over the senses.
yukta ity ucyate yogī
So when he is situated in that practical status of spiritual realization, then he is to be understood that he is actually situated in the yoga. Not that I am going to a class and, weekly or twice weekly attending yoga class, and I remain the same thing for the so many years. No. There should be practical realization. What is that practical realization? Praśāntātmā. Praśāntātmā. The mind is calm and quiet, no more agitated by the attraction of this material encirclement. You see? So jñāna-vijñāna...kūṭastho vijitendriyaḥ. The first qualification is called vijitendriyaḥ, sense control. Advancement in the yoga system means yoga indriya-saṁyamaḥ. Yoga means to... Because our whole life is disturbed due to the senses. Senses. This material life means sense gratification. That's all. The sum and substance of materialistic life means sense gratification. Therefore advancement of material science means giving you products for your sense gratification. Unnecessarily, so many things are produced just to satisfy my senses. That is the material advancement. So material life means sense gratification, and spiritual life means detached from sense gratification."
(Srila Prabhupada Lecture, New York, September 4, 1966)