Guest (5): And how does yoga…?
Prabhupāda: Oh, that is not possible for us. Because yoga practice, if you really aim to the perfection of yoga, that is not possible in this age. If you are satisfied simply by some sitting posture and paying the fees, that is your business. You can do that. But it will never get you to the perfectional stage because you are completely unable to perform all the regulation and rules of yoga system. That is not possible. That I have described in many… Yes. So yoga system is very difficult for this age. But if you think that this fractional practice of yoga, a hundredth, one percent… That is not possible to reach to the perfectional stage. The perfectional stage is that if one is perfect in the yoga practice, he shall die at his will. Material laws cannot act upon him. He’ll be practiced to control the inside air in such a way that whenever he thinks fit, that “Now I shall leave my body for such and such planet. I shall go to such and such planet,” the yoga system will help him—if he is perfect. But who is such perfect man in the yoga system? It is not possible.
Guest (2): But there have been yogis in India who have reached that…
Prabhupāda: Yes, yes, yes. But they do not come out. Because the yoga system is to practice in a secluded place alone. It is not a business that you have to open some yoga class and practice it. No. It is… First principle is that he must be alone and in a secluded place, in a sacred place. You see that they are described in the standard yoga śāstra. So they do not come, those who are really achieving perfection. They do not come out to the human society.
By His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Lecture on SB 5.5.3 — Boston, May 4, 1968