Dr. Singh: Now scientists have organized a whole department called gerontology, in which they study how to prolong life.
Srila Prabhupada: Their real aim should be to stop the suffering. Suppose an old man is in great pain, suffering from many diseases, and suddenly the doctors increase his life-span. What is the profit?
Dr. Singh: That is what they do with heart transplants.
Srila Prabhupada: It is nonsense! Let them stop death; that would be an achievement. Let them stop all disease: ah, that would be an achievement. They cannot do these things! Therefore, all their research is simply a struggle for existence. Krishna says in Bhagavad-gita [15.7], "The living entities in this conditioned world are My eternal, fragmental parts. Due to conditioned life, they are struggling very hard with the six senses, which include the mind."
Student: Now there is a shortage of oil.
Srila Prabhupada: Yes, we have built a civilization that is dependent on oil. This is against nature's law, and therefore there is now an oil shortage. By nature's law, winter is now coming. Scientists cannot stop it and turn it into summer. They wrongly think they control nature. In Bhagavad-gita Krishna says that the living being thinks himself to be the doer of activities that are in actuality carried out by nature. The sun is now rising. Can they make it dark? And when it is dark, can they command the sun, "Get up!"? They do not realize that if they really want to conquer nature, they should try to conquer birth, death, old age, and disease. In Bhagavad-gita [7.14] Krishna says, “This divine nature of Mine, consisting of the three modes of material nature, is difficult to overcome. But those who have surrendered unto Me can easily cross beyond it.”
Dr. Singh: So, is it very hard to overcome nature's laws?
Srila Prabhupada: For the materialists, it is impossible. But if one surrenders to Krishna it becomes easy.
Dr. Singh: To explain why there are so many varieties of living entities, the scientists say that at a certain time during evolution, the cells' genes, which normally reproduce themselves perfectly for the next generation, sometimes make a mistake in copying – something like the printing press that sometimes makes mistakes. In some circumstances these mistakes, or mutations, have stood, and different species of living entities have been formed because of the difference in the genes.
Srila Prabhupada: But that "mistake" has been continuing since time immemorial, for you will find that all varieties of living entities have always existed. Therefore the "mistake" is eternal. But when a "mistake" is permanent, it is not a mistake; it is intelligence!
Dr. Singh: But scientists say that without mutations there would be only one kind of living entity in the whole universe.
Srila Prabhupada: No. Every living entity has a different mind, and therefore there are so many different species of life to accommodate the different mentality. For example, we are walking here, but most people are not coming to join us, because they have different mentalities than we do. Why does this difference exist?
Dr. Singh: Maybe it is a mistake.
Srila Prabhupada: It is not a mistake. It is their desire, and at the time of death everyone will get a body exactly according to his desire. Krishna says in the Bhagavad-gita [18.61], "Whatever state of being one remembers when he quits his body, that state he will attain without fail." What you are thinking of at the time of death exactly determines your next body. Nature will give you the body; the decision is not in your hands, but in nature's, and she is working under the direction of God.
Dr. Singh: But science seems to have evidence that different species of life do arise by mistakes.
Srila Prabhupada: That is their mistake! In the laws of nature there are no mistakes. In railway cars there are first-class, second-class, and third-class sections. If you purchase a third-class ticket but by mistake go to the first-class section, you will not be allowed to stay there. It is not a mistake that there are sections: that is the arrangement. But it is your mistake that you have gone to the wrong section. So, God is so thorough that He knows all the mistakes that will be made. Therefore, according to the mistakes you commit, you enter a particular body: "Here, come here. The body is ready." There are 8,400,000 species of life, and nature works, assigning different bodies, with mathematical precision. When the government builds a city, it builds a prison even before the city is complete, because the government knows that there will be many criminals who will have to go to prison. This is not the government's mistake; it is the criminals'. Because they become criminals, they have to go there. It is their mistake.
In nature there are no mistakes. Krishna says, "This material nature is working under My direction, O son of Kunti, and producing all moving and nonmoving beings." [Bg. 9.10] Nature works under the supervision of God, Krishna, so how can nature make mistakes? But we commit mistakes, we are illusioned, our senses are imperfect, and we cheat. That is the difference between God and man. God does not have imperfect senses; His senses are perfect.
Dr. Wolf-Rottkay: Because our senses are defective, the technological enlargements of our senses, like microscopes and telescopes, must also be defective.
Srila Prabhupada: Yes. Material existence means defective existence. If you construct something with defective knowledge and imperfect senses, whatever you construct must be defective. Therefore we conclude that whatever the scientists say is defective.
Dr. Singh: But they seem quite satisfied.
Srila Prabhupada: The ass is also satisfied to carry the load of the washer man. In some parts of India one may sometimes see a dog starving to death. But as soon as it gets a female dog, it is satisfied with having sex. Is that satisfaction? The dog is starving, but still it is satisfied with sex. Everyone is satisfied, even the worm in the stool. That is nature's law.