You behold pots and cups; there must be a potter. There are tables and chairs; there must be a carpenter. You behold rice, utensils; there must be cook to prepare the food. There us the airplane, engine; there must be driver. Even so, there must be a Supreme Driver, Driver of drivers; this Driver Who drives the Prana and the senses, that Supreme Driver is the Absolute or the Eternal. That is your real nature; without this Driver this Prana and mind cannot function.
Swadhyaya is an indispensable must. Body may be able to live without food but you cannot afford to miss this inner food.