By mental speculation we cannot have into a right conclusion, by mental speculation. Those are simply speculating on mind, they can make some progress to a certain extent, but they cannot reach the ultimate goal. It is not possible by mental speculation, neither it is possible by direct evidence. The only, only possible evidence is authority. Authority.
Just like yesterday also I gave you that example. Just like if a child asks his mother that "Who is my father?" now the mother says: "Here is your father." Now, if the child says: "I don't believe it," so he has no other source of knowledge. Except the fath . . . mother's version that, "Here is your father," he has no other alternative to know who is father. It is such a thing that neither he can imagine, speculate, "Oh, he may be my father, he may be my father, he may be my father." Lots of father he can gather. That is not possible. And neither it is possible for direct perception. The only possibility is the mother's evidence.
Similarly, as the mother is authority for the child, similarly, the śruti, the Vedas, they are called mother, mother of knowledge. So for such spiritual knowledge we have to accept the authority. Now here, the Bhagavad-gītā is authority. It is accepted . . . don't think that it is a scripture of the Hindus. No. It is for all human being. There is reason. There is science. There is philosophy. It is not dogmatic. So it is to be understood simply. And not only that: actually it is accepted by all countries. Not only in your country, but in other countries also, Bhagavad-gītā is accepted as one of the greatest book of authority.
So this is the process. You should know it that the spirit soul, as it is stated in the Bhagavad-gītā:
- dehino 'smin yathā dehe
- kaumāraṁ yauvanaṁ jarā
- tathā dehāntara-prāptir
- dhīras tatra na muhyati
- (BG 2.13)
As the soul is within the body and the body is changing every moment, similarly the last stage of change is called death. Death is nothing but the final change of this present body. That's all. And our death condition is for seven months only. As soon as I leave this body, at once I am injected into other's mother's body according to my karma. I may be injected to a queen's womb, I may be injected to a dog's mother. You see? That is due to my karma. You see? The father is present there. The dog father is present there. The king father is present there. The devatā father is present there. There is no scarcity of father, but it will depend on my karma which kind of father I shall take shelter.