"I am brāhmaṇa," "I am kṣatriya," "I am vaiśya," "I am śūdra," "I am Indian," "I am American," "I am so and so." These are all bodily concept of life designations. So so long I am in bodily concept of life, I think, "I have got this duty to do. As brāhmaṇa, I have got to do such and such things." "As American, I have got to do so many things." So long this consciousness will continue, we'll have to accept another body. This is the nature's process. So long...
Therefore we make some plan in this life, and my, this material body, this gross body is finished, that is dead, but my idea, in the subtle body, in the mind, it remains. And because it remains in my mind, therefore to fulfill my desire I have to accept another body. This is the law of transmigration of the soul. The soul is, thus, with his plan, he is transferred into another gross body. And along with the soul, there is Supersoul, Supreme Personality of Godhead. Sarvasya cāhaṁ hṛdi sanniviṣṭo mattaḥ smṛtir jñānam apohanaṁ ca (BG 15.15). So the Supersoul, Supreme Personality of Godhead, gives him intelligence: "Now you wanted to execute this plan. Now you have got a suitable body and you can do it." So therefore we find that somebody is great scientist. Or a very nice mechanic. This means that in the last life he was mechanic, he was making some plan, and this life he gets chance, and he fulfills his desire. He discovers something and becomes very reputed, famous man. Because karmīs, they want three things: lābha-pūjā-pratiṣṭhā. They want some material profit and they want some material adoration, and lābha-pūjā-pratiṣṭhā, and stability. This is material life. So one after another, we are trying to have some material profit, some material adoration, material reputation. And therefore we are having different types of body.