Pravrtti and Nivrtti (प्रवृत्तिः निवृत्तिः च)
Pravrtti (प्रवृत्ति), is outward action and nivrtti (निवृत्ति), is inward contemplation. These two when governed by dharma (धर्म) , bring about even stability of the world[1].
Detailed Discussion
Adi Sankaracharya in his commentary on Bhagavad Gita mentions:
dvividho hi vedokto dharmah; pravíttilaksano nivritti-laksanah ca.
jagatah sthiti karanam praninam abhyudaya nishryasa hetuh
Translation: The dharma (धर्म) taught in Veddas is of a two-fold nature, characterized by pravrtti (प्रवृत्ति), which is outward action and nivrtti (निवृत्ति), which is inward contemplation. dharma (धर्म) brings about even stability of the world, which are meant to ensure the true abhyudaya (अभ्युदय), socio economic welfare and nihsreyasa (नि:श्रेयस), spiritual freedom of all being.
Both action and meditation are needed for human well-being. If only one or the other is there, there will be no health, individual or social. Through pravrtti (प्रवृत्ति), one establishes a welfare society through the improvement of economy and the political system. Through nivrtti (निवृत्ति) one achieves a value-oriented life that comes from humanity's inner spiritual dimension.[1]
There is stress in modern civilization because there is no emphasis on nivrtti (निवृत्ति), there is emphasis only on pravrtti (प्रवृत्ति). German philosopher Schopenhauer said: 'When men achieve security and welfare, now that they have solved all other problems, they become a problem to themselves'[2]. When there is the endless pursuit of money, power, and pleasure, the result is the creation of widespread value erosion and increasing violence[1]. All this is due to lack of nivrtti (निवृत्ति).
Therefore Sankara emphasises on Praninam saksat abhyudaya-nihsreyasa-hetuh - a philosophy of life which integrates social welfare and spiritual freedom through action and meditation[1]. Adi Sankara says that this Vedic philosophy with its twofold ideology of pravrtti (प्रवृत्ति), and nivrtti (निवृत्ति), makes for the abhyudaya (अभ्युदय) of men and women on the one side, and nihsreyasa (नि:श्रेयस), on the other[1].
An important difference between pravrtti (प्रवृत्ति) and nivrtti (निवृत्ति)
Pravrtti (प्रवृत्ति) is not required to be taught because we are naturally pravrtti prone. A child jumps up, runs about engages in pushing and pulling things; so pravrtti (प्रवृत्ति) is natural. But nivrtti (निवृत्ति) needs training. By pravrtti (प्रवृत्ति) one achieves social welfare and material well-being. For being peaceful, harmonious, fulfilled, for having capacity to love people and to live in peace with them we need the blessing of nivrtti (निवृत्ति).
Gita teaches us how nivrtti (निवृत्ति) inspires pravrtti (प्रवृत्ति). Nivrtti is required to stabilize and purify our thinking. It brings in the moral dimension and we ask questions to ourselves before any action - Why should we do this?