The whole process of creation is an act of gradual evolution and development from one element to another, reaching up to the variegatedness of the earth as so many trees, plants, mountains, rivers, reptiles, birds, animals and varieties of human beings. The quality of sense perception is also evolutionary, namely generated from sound, then touch, and from touch to form. Taste and odor are also generated along with the gradual development of sky, air, fire, water and earth. They are all mutually the cause and effect of one another, but the original cause is the Lord Himself in plenary portion, as Mahā-Viṣṇu lying in the causal water of the mahat-tattva. As such, Lord Kṛṣṇa is described in the Brahma-saṁhitā as the cause of all causes, and this is confirmed in the Bhagavad-gītā (10.8) as follows:

ahaṁ sarvasya prabhavo mattaḥ sarvaṁ pravartate iti matvā bhajante māṁ budhā bhāva-samanvitāḥ

The qualities of sense perception are fully represented in the earth, and they are manifested in other elements to a lesser extent. In the sky there is sound only, whereas in the air there are sound and touch. In the fire there are sound, touch and shape, and in the water there is taste also, along with the other perceptions, namely sound, touch and shape. In the earth, however, there are all the above-mentioned qualities with an extra development of odor also. Therefore on the earth there is a full display of variegatedness of life, which is originally started with the basic principle of air. Diseases of the body take place due to derangement of air within the earthly body of the living beings. Mental diseases result from special derangement of the air within the body, and, as such, yogic exercise is especially beneficial to keep the air in order so that diseases of the body become almost nil by such exercises. When they are properly done the duration of life also increases, and one can have control over death also by such practices. A perfect yogī can have command over death and quit the body at the right moment, when he is competent to transfer himself to a suitable planet. The bhakti-yogī, however, surpasses all the yogīs because, by dint of his devotional service, he is promoted to the region beyond the material sky and is placed in one of the planets in the spiritual sky by the supreme will of the Lord, the controller of everything.