Chapter XIV · Śloka 10
रजस्तमश्चाभिभूय सत्त्वं भवति भारत ।
रजः सत्त्वं तमश्चैव तमः सत्त्वं रजस्तथा ॥
रजः सत्त्वं तमश्चैव तमः सत्त्वं रजस्तथा ॥
rajas tamaś cābhibhūya sattvaṃ bhavati bhārata |
rajaḥ sattvaṃ tamaś caiva tamaḥ sattvaṃ rajas tathā ||
rajaḥ sattvaṃ tamaś caiva tamaḥ sattvaṃ rajas tathā ||
Sattva prevails, O Bhārata, when it overcomes rajas and tamas; rajas prevails when it overpowers sattva and tamas; and tamas prevails when it overpowers sattva and rajas.
The three guṇas are in constant competition within the psyche; whichever predominates at a given moment colors perception, motivation, and action accordingly.