Spiritual Enlightenment

Buddhism on Nirvana

According to wikipedia, Nirvana is, in Buddhism:

Nirvāṇa (Devanagari निर्वाण, Pali: Nibbāna निब्बान -- Chinese: 涅槃; Pinyin: nièpán, Japanese: nehan, Thai: Nibpan นิพพาน ), is a Sanskrit word from India that literally means extinction (as in a candle flame) and/or extinguishing (i.e. of the passions).

It is a mode of being that is free from mind-contaminants (Kilesa) such as lust, anger or craving. It is thus a state of great inner peace and contentment - the end of suffering, or Dukkha. The Buddha in the Dhammapada says of Nirvana that it is "the highest happiness." This is not the transitory, sense-based happiness of everyday life, but rather an enduring, transcendental happiness integral to the calmness attained through enlightenment.

The Buddha describes the abiding in nirvana as 'deathlessness' (Pali: amata or amaravati) or 'the unconditioned' and as the highest spiritual attainment, the natural result that accrues to one who lives a life of virtuous conduct in accordance with Dharma. Such a life (called Brahmacarya in India) dissolves the causes for future becoming (Skt, Karma; Pali, Kamma) that otherwise keep beings forever wandering through realms of desire and form (samsara).

This is mostly the Theravada interpretation of Nirvana. Mahayana Buddhism complicates things a bit with its Bodhisattva ideal. The Bodhisattva actually gives up full enlightenment in order to 'help and save humanity'. Still, divine Bodhisattvas are considered enlightened compared to 'normal human beings'. They are in effect in the possession of the knowledge of the path leading to enlightenment, because otherwise they would not have been able to give up full Nirvana.

See also Lama Surya Das on enlightenment and Buddhism on meditation and enlightenment

Moksha in Hinduism

On Moksha in Hinduism wikipedia mentions the following:

In Hinduism, liberation occurs when the individual soul (human mind/spirit) or jīvatman recognizes its identity with the Ground of all being - the Source of all phenomenal existence known as Brahman. It is technically incorrect, nonetheless, to view them - both often spoken of as Self - as a monist being of sorts, something possessing substances, qualities or attributes. In actuality, Hindu scripture like the Upanishads and Bhagavad Gita, and especially the works of the non-dualistic Hindu school, Advaita Vedanta, say that the Self or Super-Soul is formless, beyond being and non-being, beyond any sense of tangibility and comprehension. Moksha is seen as a final release from one's worldly conception of self, the loosening of the shackle of experiential duality and a re-establishment in one's own fundamental nature, though the nature is seen as ineffable and beyond sensation. The actual state of salvation is seen differently depending on one's beliefs.

The debate between Hinduism and Buddhism on enlightenment is an eternal one. It started when the Buddha denied that there was anything permanent in consciousness (the fifth skandha). It hasn't ended since. There are people who see mostly the convergence of experience and doctrines in (especially) Advaita Vedanta and Mahayana Buddhist 'Emptiness'. One example of this view is an article by Bijoy H. Boruah 'Atman in Sunyata and the Sunyata of Atman'.