Nal-pathi is a Tamil theological term meaning 'the good/virtuous path' (nal = good, pathi = path/way). In Śrī Vaiṣṇava discourse it primarily denotes prapatti — the path of total surrender to Bhagavān or the Āchārya — as the correct and efficacious means (upāya) for the jīva. It is set in contrast to kupath, which refers to paths premised on the jīva's own agency, effort, or merit: elaborate karma-yoga routines or elaborate jñāna-yoga practices undertaken without the foundational recognition of one's śeṣatva (servanthood) to Bhagavān.
In the Āzhvār corpus, the term and its cognates appear in contexts where the poet has found the Lord through grace alone, turning away from worldly or spiritually vain pursuits. The image of 'path' is significant: a path must be identified, chosen, and walked — nal-pathi is a teaching that the very act of choosing to surrender is itself the path, unlike bhakti-yoga which requires sustained independent effort over lifetimes. Maṇavāḷa Māmunigaḷ's commentaries frequently distinguish nal-pathi from seemingly plausible alternatives that are actually dead ends.
The term also carries a lineage dimension: the sampradāya's chain of Āchāryas is itself called the nal-pathi, the true path of transmission. One who follows the Āchārya-paramparā is on the nal-pathi; deviation from the paramparā's teaching — whether through innovation, ego, or misinterpretation — is kupath. This sense preserves the organic connection between the metaphysical path (prapatti) and its institutional vehicle (the Āchārya lineage).