There are six main darshans -- schools of Indian philosophy. One of them is Samkhya, which believes that all human reality is generated by the interactions of two independent entities. These are the purusha -- consciousness or spirit, and the prakriti -- nature or mind. Purusha has no attributes and is unknowable, above any experience by mind or senses, and beyond any words or explanations. It cannot be substantialised or objectified. Prakriti, on the other hand, consists of all animate and inanimate objects and mental experiences, and is made up of three gunas -- qualities.
These three gunas are present in all beings and things of this world. They are sattva (purity), rajas (activity), and tamas (darkness). The three gunas are like three threads that are intertwined together to make the fabric of this world. The major texts that discuss the three gunas are the Upanishads, the Buddha-charita, and the Bhagavad Gita.
Tamas stands for darkness and impurity. It generates feelings of delusion, hatred, and anger. It makes a person dull, and sleep too much. The person either does not do anything or engages in activities that are not life-supporting. Tamas has been called the greatest enemy of humans.
Rajas stands for restlessness, desire and aggression. It makes a person hyperactive. The phrase ‘ants in the pants’ is apt for persons ruled by rajas guna. Ultimately, rajas causes sadness, as the person is not satisfied by anything. Rajas can be good or bad. If you don’t have any rajas guna at all, you cannot complete any work. But too much of rajas causes cruelty, carelessness, impatience and anxiety.
Sattva stands for joy, happiness, knowledge, clarity, awareness, presence of mind, and harmony. It makes a person friendly and eager to learn. When you have slept well, you feel very alert and clear-minded. Everything seems bright and we feel happy. This is the moment when sattva guna is dominating. If tamas is darkness, sattva is light. Sattva leads to contentment.
In Bhagavad Gita, Sri Krishna says action is better than inaction. This means that if our main guna is tamas, we must try to move towards rajas. Any kind of action is better than inaction. Once we have started doing an action, the next stage is to think about what kind of action we should do. Sri Krishna tells us that nishkama karma (selfless action) is better than selfish action.
This will move us from rajas to sattva. Sattva can be increased by meditation, serving others, eating right, and having the right amount of exercise. In life, our goal should be to reduce the lower gunas and increase the higher gunas till we become completely sattvic.