The Need for Dzogchen
Dzogchen (rdzogs-chen, the great completeness) is an advanced system of Mahayana practice that brings enlightenment. It is found primarily in the Nyingma and Bon traditions, but also appears as a supplementary practice in some of the Kagyu traditions such as Drugpa, Drigung, and Karma Kagyu. Let us speak here of dzogchen as formulated in the Nyingma school.
To reach enlightenment, we need to remove forever two sets of obscurations:
emotional obscurations (nyon-sgrib) – those that are disturbing emotions and attitudes and which prevent liberation,
cognitive obscurations (shes-sgrib) – those regarding all knowables and which prevent omniscience.
These obscurations bring us, respectively, the suffering of uncontrollably recurring existence (samsara) and the inability to be of best help to others. They are fleeting (glo-bur), however, and merely obscure the essential nature (ngo-bo) of the mind and limit its functioning. In essence, the mind (mental activity) is naturally pure of all fleeting stains. This is an important aspect of its Buddha-nature.
[See: Ridding Oneself of the Two Sets of Obscurations in Sutra and Anuttarayoga Tantra According to Nyingma and Sakya.]
In general, to remove both sets of obscuration requires bodhichitta (byang-sems) and nonconceptual cognition of voidness (stong-nyid, Skt. shunyata, emptiness) – the mind’s natural absence of fleeting stains and its absence of impossible ways of existing (such as inherently tainted with stains). Bodhicitta is a mind and heart aimed at enlightenment, with the intention to attain it and thereby to benefit all beings as much as is possible. Removing obscuration also requires a level of mind (or mental activity) most conducive for bringing about this removal. Dzogchen practice brings us to that level.