That is described in the Bhagavad-gītā, yantrārūḍhāni māyayā (BG 18.61). It is a machine given by māyā, the material energy. Asat. Just like the aeroplane is also a machine. It has no life. But life is the pilot. So long the pilot is there, the machine is useful. If there is no pilot, it may stand in the airport for millions of years; it will not fly. Very practical.
Still, they are very much proud of this body. Why? Alpa-buddhayaḥ, it is said, "less intelligent." Less intelligent. So why he has become less intelligent? That is described in this verse, kāmam āśritya. His basic principle of life is lusty desire, āśritya. He has taken shelter of principally the lusty desire, kāmam āśritya. Our constitutional position is we have to take shelter of somebody. Just like the dog. The dog, if he has no shelter, a good master, he has no position. Street dog.