I am studying the Visuddhimagga’s exposition on Nibbāna. A citta is lokuttara because it takes the unconditioned nibbāna as its object, thus entirely circumventing dukkha.
However, nibbāna is an asaṅkhata dhamma lacking active agency. The severing of saṃsāra is executed by the lokuttara citta itself (right?). Given that this citta remains fundamentally conditioned (saṅkhata), by what principle does a conditioned mental state possess the power to permanently shatter saṃsāra by cognising an unconditioned object?
It removes the causes. It does not remove saṃsāra.
The supramundane path consciousness (lokuttara-maggacitta) is an active, kammically wholesome (kusala) state. Its specific function is to actively eradicate the defilements (kilesas) and fetters (saṁyojanas) through severance (samucchedappahāna). It performs this intense work in a single mind-moment.
samucchedappahānañca lokuttaraṃ khayagāmimaggaṃ bhāvayato; paṭippassaddhippahānañca phalakkhaṇe.
Abandonment by cutting off (samucchedappahāna) occurs when one develops the supramundane path that leads to the destruction (of defilements); abandonment by tranquilization (paṭippassaddhippahāna) occurs at the moment of fruition. tīṇi pahānāni – kāmānametaṃ nissaraṇaṃ yadidaṃ nekkhammaṃ; rūpānametaṃ nissaraṇaṃ yadidaṃ āruppaṃ; yaṃ kho pana kiñci bhūtaṃ saṅkhataṃ paṭiccasamuppannaṃ, nirodho tassa nissaraṇaṃ.
Three abandonments – the escape from sensual pleasures is renunciation (nekkhamma); the escape from forms is the formless attainments (āruppa); and whatever is arisen, conditioned, and dependently originated, its cessation is the escape.
pajahatīti samucchedappahānavasena ariyamaggena pajahati.
“He abandons” means he abandons with the noble path, by way of abandonment by cutting off. tattha kilesapaṭipāṭiyā maggapaṭipāṭiyāti dvidhā pahānaṃ veditabbaṃ.
Therein, abandonment should be understood in two ways: by the sequence of defilements and by the sequence of the paths. kilesapaṭipāṭiyā tāva abhijjhāvisamalobho thambho sārambho māno atimāno madoti ime cha kilesā arahattamaggena pahīyanti.
Firstly, by the sequence of defilements, these six defilements—covetousness and unrighteous greed, obstinacy, rivalry, conceit, arrogance, and intoxication—are abandoned by the path of Arahantship.
851. yaṃ pana asanivicakkābhihatassa rukkhassa viya ariyamaggañāṇena saṃyojanādīnaṃ dhammānaṃ yathā na puna pavatti, evaṃ pahānaṃ, idaṃ samucchedappahānaṃ nāma.
851. The abandonment whereby the defilements such as the fetters do not arise again through the knowledge of the Noble Path, just as a tree struck by a lightning bolt does not grow again—this is called samucchedappahāna. 338yaṃ sandhāya vuttaṃ ‘‘samucchedappahānañca lokuttaraṃ khayagāmimaggaṃ bhāvayato’’ti (paṭi. ma. 1.24).
It is with reference to this that it is said: “And samucchedappahāna for one developing the supramundane path leading to destruction.”
But whatever there is of wisdom; of penetration; of right view conjoined with the path - the holy path being pursued; this is called the supermundane right view (lokuttarasammādiṭṭhi); which is not of the world; but which is supermundane and conjoined with the path.”