Lord Kṛṣṇa says in Bhagavad-gītā (BG 15.7):
- mamaivāṁśo jīva-loke
- jīva-bhūtaḥ sanātanaḥ
- manaḥ-ṣaṣṭhānīndriyāṇi
- prakṛti-sthāni karṣati
"The living entities in this conditioned world are My eternal, fragmental parts. Due to conditioned life, they are struggling very hard with the six senses, which include the mind."
Here it is also explained that the living entity comes in contact with the sixteen material elements and is influenced by the three modes of material nature. The living entity and this combination of elements combine to form what is called jīva-bhūta, the conditioned soul that struggles hard within material nature. The total material existence is first agitated by the three modes of material nature, and these become the living conditions of the living entity. Thus the subtle and gross bodies develop, and the ingredients are earth, water, fire, air, sky, and so on. According to Śrī Madhvācārya, when consciousness, the living force in the heart, is agitated by the three modes of material nature, then the subtle body of the living entity, consisting of the mind, the sense objects, the five senses that acquire knowledge and the five senses for acting in the material condition, becomes possible.