(Prabhupada's lecture - Śrīmad-Bhāgavatam 2.1.2 – Paris, June 11, 1974)
Therefore Kṛṣṇa points out in the Bhagavad-gītā that real freedom is when you get freedom from four different problems. What is that? Janma-mṛtyu-jarā-vyādhi-duḥkha-doṣānudarśanam [Bg. 13.9]. If you get freedom from these four things—no more death, no more birth, no more old age, old age, and no more disease—that is freedom. But where is that freedom? The so-called scientists, big, big scientists, they have very scientifically advanced, but they had no freedom from death. They had to die on a fixed-up date. Professor Einstein or any other big, big scientist, they could not manufacture any scientific instrument and keep it in the custody of his student, that "As soon as I die, you just apply this machine. I shall come alive again." Where is that freedom?
So this so-called scientific improvement, advancement in civilization, it is just like jumping like the dog. That's all. It has no value. Real value is to understand ātma-tattvam, "What I am? Why death is imposed upon me? I do not wish to die. Why old age is imposed upon me? I do not wish to become old man or old woman. I wish to remain a beautiful young..." "No, sir, that is not possible." Then where is your freedom? What for you are jumping so much? As soon as the master will call "Yes, sir. Bind me..."