At the present age, mostly the scientists, they cannot give us perfect knowledge, because there are so many "if's." They say, "It may be," "Perhaps," like that. But this is not perfect knowledge. The perfect knowledge means there is no "if," there is no "perhaps," there is no doubt. So we are receiving knowledge from Kṛṣṇa, the supreme perfect being. He says that dehino 'smin yathā dehe (BG 2.13). Asmin dehe. Asmin means this, this body. You have got your body, I have got my body. So within this body, there is the proprietor of the body. Asmin dehe. Dehinaḥ asmin. Dehe means the proprietor of the body. I do not see you—I see your body, you see my body. But within the body the proprietor is lying, or he is situated. That we do not see. But we can understand. Suppose my beloved father is dead or somebody is dead. I cry, "My father is gone." So where is your father gone? He is lying there, unconscious. He may come to consciousness again. But we say: "No, he is gone." "Dead" means gone. So factually I never saw my father who has gone. I saw the body of my father, and that is lying on the bed. Why I am crying, "My father is gone"? Therefore this is called ignorance. We do not see the real father within the body, or we do not see the real son within the body. We see the outward dress only. This is ignorance.
So we are preaching Kṛṣṇa consciousness movement on the platform of the spirit soul, which we do not see with these material eyes. This is great ignorance. After the death we cry that, "My father is gone," "My son is gone." But where he has gone? He is lying on the bed. Now, even still, we do not come to the understanding what is the difference between the living body and the dead body. There are so many theories, but as I have already told you that we receive knowledge from the perfect person, Kṛṣṇa.