changed." I  want  to jump, but I cannot do it. That jumping propensity is eternal, but because of my old body I cannot do it.
Dr. Singh.  Opponents will say that according to their observation, the nature of consciousness is that it lasts for only one body.
Śrīla Prabhupāda . That is foolishness. In  Bhagavad-gītā  (2.13) Kṛṣṇa explains:
dehino 'smin yathā dehe kaumāraṁ yauvanaṁ jarā tathā dehāntara-prāptir dhīras tatra na muhyati
"As the embodied soul continually passes, in this body, from boyhood to youth to old age, the soul similarly passes into another body at death. The self-realized soul is not bewildered by such a change." Just as this body is always changing (as I can see in my daily experience), there is a similar change at the time of death.
Dr. Singh.  But according to the scientists, we cannot actually  observe  this last change.
Śrīla Prabhupāda.  Their eyes are so imperfect that they cannot observe many, many things. Their ignorance does not make the  Bhagavad-gītā  unscientific. Why don't the scientists admit the imperfection of their senses? They must first admit the imperfection of their senses. Their seeing power does not determine what is and what is not science. Dogs cannot understand the laws of nature. Does that mean the laws of nature don't exist?
Dr. Singh.  Well, the scientists admit that argument, but they say the way to become perfect is through objective information and experience.
Śrīla Prabhupāda.  No. That is not the way to become perfect. No one can become perfect through imperfect thinking, and our thinking must be imperfect because our senses and minds are imperfect.
Dr. Singh.  Śrīla Prabhupāda, another question can be raised. is it not possible that the soul may accept three, four or five bodies and then die?
Śrīla Prabhupāda.  You are accepting millions of bodies. I say that your body of yesterday is not your body of today. So, if you live for one hundred years, how many times have you changed bodies? Just calculate.
Dr. Singh , Thirteen,
Śrīla Prabhupāda.  Why thirteen?
Dr. Singh.  Medical science says that all the bodily cells are replaced every seven years.
Śrīla Prabhupāda.  No, not every seven years- every second . Every second, the blood corpuscles are changing. Is it not so?
Dr. Singh  Yes.
Śrīla Prabhupāda . And as soon as the blood corpuscles change, you change your body.
Dr. Singh.  In scientific terminology, can the eternality of the soul be compared to conservation of energy?