In the philosophy
of Yoga, all matter in the universe arises from the fundamental
substrate called Prakriti. From this ethereal Prakriti the three primary
gunas (qualities) emerge creating the essential aspects of all
nature—energy, matter and consciousness. These three gunas are tamas
(darkness), rajas (activity), and sattva (beingness).
Sattva is a state of harmony, balance, joy and intelligence. Sattva is the guna that yogi/nis achive towards as it reduces rajas and tamas and thus makes liberation possible. To increase sattva reduce both rajas and tamas, eat sattvic foods and enjoy activities and environments that produce joy and positive thoughts. Sattvic foods include whole grains and legumes and fresh fruits and vegetables that grow above the ground. All of the yogic practices were developed to create sattva in the mind and body. Thus, practicing yoga and leading a yogic lifestyle strongly cultivates sattva.
psychological qualities are highly unstable and can quickly fluxuate
between the different gunas. The predominate guna of the mind acts
as a lens that effects our perceptions and perspective of the world
around us. Thus, if the mind is in rajas it will experience world events
as chaotic, confusing and demanding and it will react to these events in
a rajasic way.