Bhagavad Gita · Chapter 14: The Three Qualities of Nature
Bhagavad Gita 14.10
रजस्तमश्चाभिभूय सत्त्वं भवति भारत ।
रजः सत्त्वं तमश्चैव तमः सत्त्वं रजस्तथा ॥
rajastamaścābhibhūya sattvaṃ bhavati bhārata | rajaḥ sattvaṃ tamaścaiva tamaḥ sattvaṃ rajastathā ||
Clarity prevails by overpowering passion and inertia, Arjuna; passion by overpowering clarity and inertia; and inertia by overpowering clarity and passion.
Modern context
The three are always competing. When one rises, it overpowers the other two. No one is purely one type; the balance shifts through the day, through seasons, through life. This is hopeful. It means a person is not fixed. By choosing what to eat, how to sleep, what to watch and whom to spend time with, one can tip the balance toward clarity.