The main vedic-yogic system of understanding, assessing, and addressing the needs of the mind and the emotions is the triguna system. This system is like a lens through which we may view everything in existence as the division into and interactions between 3 basic qualities called gunas.
Tamas is metaphorically described as pertaining to darkness and heaviness, oriented towards the past and arising from it as karmic consequences of past actions. While tamas is naturally involved in the arising of all forms, such as the body, an excess of tamas results in mental heaviness: depression, nostalgic sadness, mulish stubbornness, pathological materialism and grasping attachment. An excess of tamas may arise from unaddressed mental patterns of insecurity, overeating, oversleeping, or overaccumulation of possessions.
Rajas pertains to the fire of unbridled passions, primarily oriented towards the future in a relationship of desire and greed. While rajas is naturally involved in drive and action in the world, fueling forward motion in life through the wish for expression and meaningful impact in life, an excess of rajas results in mental aggression: unbridled anger, powerful craving, jealousy, zeal, and selfish drive without consideration for the needs of others. An excess of rajas may arise from hyperactivity, hypersexuality, or aggressive language, music and marketing.
Sattva refers to the qualities of light, both in weight and in brightness. It is described as the energy of love, peace, joy and wisdom, and is entirely oriented towards the present moment. Much of the purpose of yoga may be said to be cultivating sattva, which may be achieved through meditation, mantra, service, selfless prayer, generosity, and acts of kindness and consideration.
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