20 Krṣṇa Consciousness: the Topmost Yoga System
The  Bhagavad-gītā  says that just as our outer garments are changed, so this body is changed.  Yoga  means the process of getting out of this material embodiment. Just as you are repeating changes of dress, so you are repeating birth and death, and this is the cause of your miseries. If you do not understand this, then all your activities end in defeat.
Yoga  means to get out of this embodiment, and it means to know oneself. This body is born of the parents. Similarly, as pure soul, you are also the source of its birth. We do not mean birth beginning historically from a certain day and ending on a certain day. No; the soul is not like that—it has no beginning, and it has no end. But in the  Bhagavad-gītā  it is said that the soul is part and parcel of God. God is eternal, God is full of joy and bliss. The position of the Absolute Person, the God-head, is that He is full of bliss, eternal, and full of knowledge. And, because we are also part and parcel of the Supreme, we have partial blissfulness and eternality, and we are full of knowledge, according to our infinitesimal size.
The human beings are understood to be the most intelligent of all living creatures, but they are misusing their intelligence. How? They are misusing their intelligence by devoting it to the animal propensities. These animal propensities are eating, sleeping, mating and fearing. You can analyze the trend of modern civilization: everyone is busy with these four principles of animal life. They are sleeping and creating some cushions for comfortable sleep. They are creating palatable dishes for the eating propensity. They are exciting sex very nicely, for the mating necessity. And they are defending their country with so many atom bombs—that is the fear propensity.
But these symptoms you will find among the animals. They are also sleeping according to their own ways, and they are defending. They may not have the atom bomb, but they have some way of defending. You can kill your enemy, or he can kill you, but there is actually no defense. You cannot defend