Spiritual life and material life, what is the difference? Material life means the bodily concept of life, "I am this body." This concept of life is prevalent amongst the animals. In the Śrīmad-Bhāgavatam it is said, yasyātma-buddhiḥ kuṇape tri-dhātuke (SB 10.84.13). Kuṇape means bag. This body is a bag made of blood, bones, marrow, muscles, and stool, urine, pus, nails, hair, like that. Everyone can understand. If you analyze this material body, what ingredients you will find? These things you will find. These things you will find in animal's body also—blood, muscles, flesh, bones, stool, urine, nails, hair, like that. So these are the ingredients of the material body.
They are, materialistic scientists, they are studying the brain substance, but what is this brain substance? This is also matter. Brain substance actually do not work. That is something else. That is, that information is being given here: dehino 'smin yathā dehe (BG 2.13). Within this body there is the proprietor of the body. Just like, what is that computer machine? Very subtle machine. Or this tape recorder, or any other . . .
Nowadays so many subtle machines are manufactured, and they are working very wonderfully. Just like the television machine, it has no connection with . . . where or anything, and still exactly the photograph, the sound and everything is coming from outside, and you are seeing in your room things as they are, even with color. So it is very subtle machine undoubtedly. But the subtle machine is working not independently. They . . . there is a man who is working