不動滅Immovable cessation, the unconditioned
無為法之第四。「苦樂受滅」（CWS 卷二）為體，「第四靜慮之無動搖性」為其 aspect-名——非另立一「不動之法」，乃真如於第四禪境之「苦樂離繫性」面向之假立命名（→#95 5-依真如假立框架已詳）。百法原文為「不動滅無為」（含滅字，T31n1614），「不動無為」為後代常見簡稱；「滅」字保留「苦樂之滅」之cessation 性格。
漢zh · Xuanzang 譯
無為法之第四。「苦樂受滅」（《成唯識論》卷二）為體，「第四靜慮之無動搖性」為其面相名——非另立一「不動之法」，乃真如於第四禪境之「苦樂離繫性」面向之假立命名（→#95 5-依真如假立框架已詳）。百法原文為「不動滅無為」（含滅字，T31n1614），「不動無為」為後代常見簡稱；「滅」字保留「苦樂之滅」之cessation 性格。
經
[共傳] 《中阿含經》第四禪定義（T01n0026 多處）：
彼已斷此五蓋……至得第四禪成就遊。彼得如是定，心清淨，無穢無煩，柔軟善住，得不動心，趣向漏盡智通作證。
——「得不動心」為第四禪之canonical 漢譯特徵語。⚠️ 此 formula 遍見《中阿含》第四禪諸定義段，具體卷次待 v2.1 CBETA 精確核對。「柔軟善住，得不動心」與 Asg 梵本所指（離遍淨欲之階位，sukha 已滅）之層次對應。
《雜阿含經》九次第定（T02n0099）：
第四禪正受時，出入息寂滅。
——第四禪「出入息寂滅」為苦樂俱離之果——南北傳皆確認此經典 formula（巴利四禪公式同云 assāsapassāsā niruddhā）。
[大乘] 《楞伽阿跋多羅寶經》（求那跋陀羅譯，T16n0671）卷三（待 CBETA 卷次確認）：
自覺聖智善樂……住第八菩薩地。
——「不動地」（acalā-bhūmi，菩薩八地）之「不動」為大乘對「不動」義之深化——由第四禪 sukha 滅之靜止，拓展至無生法忍之不退轉。⚠️ 楞伽有三譯（菩提流支 T0670 / 求那跋陀羅 T0671 / 實叉難陀 T0672）；「自覺聖智善樂」措辭屬 《入楞伽經》 風格；卷三之具體行位（T16.0xxx）待 CBETA 精確核對。
論
論藏定義由淺入深三層，三框架架構揭示 Asg 與顯揚／《成唯識論》之 sukha-only vs 苦樂分歧：
《大乘阿毘達磨雜集論》卷二（T31n1606，安慧釋《集論》）：
不動者，謂已離遍淨欲、未離上欲，苦樂滅無為。
——「已離遍淨欲」即超越第三禪（遍淨，śubhakṛtsna）之喜樂；「未離上欲」即未及無色界貪——故住第四靜慮。「苦樂滅無為」此處循顯揚／CWS之擴展讀（苦樂俱離），見下表。
《顯揚聖教論》卷一（T31n1602, T31.0484c04–05，無著菩薩造）：
不動者，謂離遍淨欲得第四靜慮，於其中間苦樂離繫性。
——顯揚擴展為苦樂俱離之「離繫性」（visaṃyoga-tā）——與 Asg 梵本 sukha-nirodha（樂滅獨）有所出入（見梵段三框架表）。「離繫性」為面相分層式命名：不動非事相（事相面另在第四禪正受之有為流），乃真如於此境之面相。
《成唯識論》卷二（T31n1585, T31.0006c15，六無為假立論；「五依真如假立」框架全塊見 →#95 5-依真如假立框架已詳）：
苦、樂受滅，故名不動。
——《成唯識論》取精簡措辭，循顯揚之苦樂讀；此一行為「五依真如假立」框架中不動之面向命名（→#100 真如承擔 the 統合者 role）。
按：論藏三層揭示一組織性分歧——Asg 梵本最窄（sukha-nirodha 樂滅獨），顯揚擴展至苦樂俱離，《成唯識論》循顯揚讀。Asg 之義最精確（第四禪「最新所離」之特徵事件為三禪喜樂），顯揚／《成唯識論》之義與巴利四禪公式（sukhassa ca pahānā dukkhassa ca pahānā）相符，二義均屬正典（→梵段三框架表詳）。《成唯識論》以面相分層方式，將苦樂離繫性命名為真如之面向，非另立「不動之實有法」——此為本條之 prajñapti 性格（→#95 5-依真如假立框架；→#100）。
梵saṃskṛta
āniñjya — 形態解析：a-（否定前綴）+ āiñjya，其中 āiñjya < ā-（強化前綴）+ √iñj（搖、動、振）+ -ya（形容詞化後綴）——「不可動搖」「不可撼動」。āniñjya 即「āiñjya（可搖動者）之否定形」。√iñj 之 causative 形式為 iñgati（「使動、搖動」），見於梵語文學詞彙。⚠️ 印歐祖語重構：若干二手文獻提議 √iñj 與印歐祖語 *h₁enǵʰ- 或 *h₁eyǵ-（「動、震」）有關，然 Mayrhofer EWAIA 及 Lubotsky Indo-Aryan Inherited Lexicon 未予 secure；誠實立場：印度雅利安語系內有豐富同根詞群（iñgati, iñgana, iñg-），印歐祖語上游待考，保留 ⚠️。不上推為 secured 印歐祖語鏈。
變體拼法：āneñjya（含 e 元音）見於瑜伽師地論及部分顯揚傳本；Pāli 形式為 āneñja；Asg 梵本形式為 āniñjya。
《阿毘達磨集論》（阿毘達磨-samuccaya，Pradhan 校本，asaṃskṛta-dharma 段，[Abhidh-s 13]）：
āniñjyaṃ katamat / śubhakṛtsna-vītarāgasya upary-avītarāgasya sukha-nirodhaḥ //
（GRETIL（哥廷根大學印度語典電子文獻檔） raw：ānijyaṃ katamat / śubhakṛtsnavītarāgasyoparyavītarāgasya sukhanirodhaḥ //；ānijyaṃ → āniñjyaṃ anusvāra 正規化。）
何為不動？對於已離遍淨（śubhakṛtsna）欲、未離其上欲者（即住第四靜慮者），樂（sukha）之滅（sukha-nirodha）。
Asg 之義最窄且最精確：第四禪之定義事件為 sukha（三禪之喜樂）之滅，而非苦樂俱滅——因苦（duḥkha，欲界之苦）早於初禪已離，故第四禪「最新所離之一項」為 sukha。Asg 之止息-by-designation 定義式：無 svabhāva / karman 雙結構（同 #95 梵段已闡明之無為類定義原則）——āniñjya 非「有自體有業用之法」，乃階位特徵之命名。
三框架架構（Asg → 顯揚 → 《成唯識論》之 sukha vs 苦樂分歧）：
| 文本 | 第四禪所滅 | Frame |
|---|---|---|
| Asg 梵本 [Abhidh-s 13] | sukha-nirodha — 樂（獨） | 最窄 / 最精確 |
| 顯揚（T31.0484c04–05） | 苦樂離繫性 | 擴展（含苦） |
| 《成唯識論》卷二（T31.0006c15） | 苦、樂受滅 | 循顯揚擴展讀 |
二義均屬正典：Asg 義精確析別（第四禪特徵事件）；顯揚／《成唯識論》義與巴利四禪公式（sukhassa ca pahānā dukkhassa ca pahānā）相符，呈現整體 dhyāna-sequence 之觀。
按：Asg 梵本之止息-by-designation 定義式於本詞族一貫——āniñjyaṃ katamat 之 katamat（「何為」）+ 簡短功能子句，無 svabhāva / karman 雙結構（→#95 梵段已闡明）。本條三框架表（Asg／顯揚／《成唯識論》）繼承 #95 梵段表之方法論樣板（→#95）。本條（#98）與 →#96 擇滅／→#97 非擇滅同為四止息-type 無為之一員，然本條之 Pāli 同源關係最為曲折——非「南傳無對應」（如 #97），而是「南傳有 aneñja 詞，然歸屬有為行蘊，與本條之無為判攝截然相反」——詳巴段。
巴pāḷi
Pāli āneñja（梵 āniñjya 之巴利形式；e 元音為規則音變，ñj → ñj 保留）。
判攝差異——同根異類（categorial reversal）
南北傳均有 āneñja / āniñjya 此詞，然歸屬範疇截然相反：
| 傳統 | 詞形 | 範疇歸屬 | 文本根據 |
|---|---|---|---|
| 南傳 | aneñjābhisaṅkhāra | 有為法，行蘊之 saṅkhāra-類 — 第四禪以上所積之「不動業行」 | SN 12.51, AN 4.171；Vism XVII（paṭicca-samuppāda 章） |
| 北傳瑜伽行派（百法） | 不動滅無為 (āniñjya) | 無為法，第四靜慮之苦樂滅所顯之真如面向 | Asg [Abhidh-s 13]；《成唯識論》卷二 T31.0006c15 |
⭐⭐⭐ 「同根異類」之深層邏輯：南傳視第四禪以上禪定所積之業為「不動業行」（aneñjābhisaṅkhāra）——此業不可被動搖，故曰「不動」；歸屬有為行蘊（有為 saṅkhāra-類），為三類業行（puñña- / apuñña- / āneñja-abhisaṅkhāra）之第三。北傳則將同一「不動」所指之現象學——第四禪苦樂滅之離繫性——提升為無為，命名為不動滅無為。同詞根、同禪定現象、反本體論歸屬（架構框架詳 §4.8）。
南傳四禪相關 loci
南傳四禪之經典 formula（DN 2 Sāmaññaphala Sutta；MN 36 Mahāsaccaka Sutta 等）：
sukhassa ca pahānā dukkhassa ca pahānā ... catutthaṃ jhānaṃ upasampajja viharati
——「以苦之捨、樂之捨……入住第四禪」。此公式與顯揚／《成唯識論》之「苦樂受滅，故名不動」同向，確認苦樂俱離為四禪之經典描述（與 Asg 梵本 sukha-nirodha 之精確析別不同——南傳四禪公式呈現整體觀，Asg 析別「最新所離一項」）。
俟終校 — SN 12.51 之 aneñjābhisaṅkhāra Pāli 原文確切措辭，及 Vism XVII 段落位置：驗證報告確認節參照，但字元精準原文待 v2.1 核補；此處以節描述代替，不生成 Pāli 引文。
按：南傳之「不動業行」（aneñjābhisaṅkhāra，有為）與北傳之「不動滅無為」（āniñjya，無為）之範疇對立，為六無為條目中跨傳統落差最顯著之例——非如 #96 擇滅之「南傳僅立 Nibbāna，概念最近」，非如 #97 非擇滅之「南傳完全無結構對應」，而是同詞根現象在兩傳統中被主動分別納入有為行蘊（南傳）與無為假立（北傳）。此分判反映兩傳統對「無為應如何 categorize」之系統決定（架構框架詳 §4.8）。
漢綜述zh-synthesis
「不動滅」之梵文 āniñjya 為 a-（否定前綴）+ āiñjya，其中 āiñjya < ā-（強化前綴）+ √iñj（「搖、動、振」）+ -ya（形容詞化後綴）——「不可動搖」「不可撼動」。梵語自身之同根詞：iñgati（「使動、搖動」，√iñj 之動詞形）。⚠️ 印歐祖語重構：若干二手文獻提議 √iñj 與 *h₁enǵʰ- 或 *h₁eyǵ-（「動、震」）有關，然 Mayrhofer EWAIA 及 Lubotsky 未予 secure；保留為印度雅利安語系內部，不上推。Pāli 形式 āneñja（含 e 元音）為規則音變（i → e before ñ），與梵 āniñjya 為精確同源詞；兩者共指同一第四禪之「不動」現象，然南北傳歸屬範疇截然相反（詳南北段）。百法原文「不動滅無為」（T31n1614），「滅」字保留 cessation 性格；「不動無為」為後代常見簡稱。此為 6 無為之第四。
不動滅義理核心在《集論》梵本之最窄、最精確定義：「已離遍淨（śubhakṛtsna）欲、未離上欲」者（即住第四靜慮者）之 sukha（樂）之滅（sukha-nirodha）——因 duḥkha 早於初禪已離，第四禪「最新所離之特徵事件」為三禪之喜樂，故 Asg 以「樂滅」精確析別。顯揚與《成唯識論》擴展為「苦樂俱離」（苦、樂受滅），與巴利四禪公式（sukhassa ca pahānā dukkhassa ca pahānā）相符，呈整體觀；兩讀均屬正典。於「五依真如假立」中，「苦樂受滅，故名不動」（《成唯識論》卷二）——不動為真如於第四禪境之「苦樂離繫性」面相之假立命名，第四禪所顯（→#95 5-依真如假立框架已詳；→#100 承擔統合者）。
南傳有精確同源詞 aneñja（梵 āniñjya 之巴利形式），然歸屬範疇截然相反：南傳將 aneñjābhisaṅkhāra（「不動業行」）判為有為法之 saṅkhāra-類（行蘊之第三業行類——善業行／不善業行／不動業行，見 SN 12.51, AN 4.171；Vism XVII），即第四禪以上禪定所積之「不動業行」，有為，能引不動地結生；北傳瑜伽行派則將同一第四禪之「不動」所指——苦樂離繫性——提升為無為法（asaṃskṛta）。同詞根、同禪定現象學、反本體論歸屬：南傳視之為有為行蘊之業行類，北傳視之為真如之無為面相假立。此乃 6 無為 cluster 中同源詞-反本體論狀態之例（→#95 南北分歧框架）。
第四禪之禪觀要點：行者於第三禪之喜樂（sukha）中，識別喜樂本身仍為微細之執取對象——此執取被捨離後，所現之品質即「不動」：不被苦樂任一極傾動，upekkhā（捨）與 ekaggatā（一境性）具足。《成唯識論》「苦、樂受滅，故名不動」所指之真如面相：非修行所「創造」之新事物，乃「苦樂受滅」此離繫性於真如上之面相命名。真如（→#100）於苦樂活躍時與受寂靜時同等在場；「不動」為第四禪之現象學成就，真如為其底層原理。
「不動滅無為」百法原文；後代「不動無為」為常見簡稱。英譯 Immovable cessation, the unconditioned 保留 cessation 性格（「滅」字所示），以 immovable 對 āniñjya「不可動搖」，以 the unconditioned 標明 asaṃskṛta 範疇。
不動滅 ——於苦樂受滅之 dharmatā-面相中（第四禪所顯），假立「不動滅」（āniñjya，Pāli āneñja）之名；性為苦樂受寂止之非搖動離繫位，業為禪定苦樂離繫性之施設；不變不滅之究竟實，依真如（→#100）之苦樂受滅面相假立。
英綜述en-synthesis
Sanskrit āniñjya compounds the privative prefix a- (not) with āiñjya, itself derived from the intensive prefix ā- plus the root √iñj "to move, to shake, to stir" plus the adjectival suffix -ya. The compound reads: "that which is not-āiñjya" — i.e., "the non-shakeable, the immovable." √iñj appears in Sanskrit as iñgati "it moves, it stirs," and the causative iñgayati "to cause to move." PIE upstream is debated: some sources propose connection with *h₁enǵʰ- or *h₁eyǵ- "to move," but Mayrhofer's Etymologisches Wörterbuch des Altindoarischen and Lubotsky's Indo-Aryan Inherited Lexicon do not confirm a secure reconstruction. Honest position: the Indo-Aryan-internal cognate set (iñj-, iñgati, āniñjya, āneñja) is internally consistent; the PIE chain is uncertain. No English cognate chain is established. The Pāli form āneñja reflects the regular development i → e before ñ. The variant spelling āneñjya (with -ya suffix preserved) is also attested in Yogācāra texts including the Yogācārabhūmi tradition. A terminological note on near-synonyms: the Yogācāra and Buddhist iconographic traditions produce a second "immovable" compound, Akṣobhya (阿閦佛, the Tathāgata of the eastern direction), from the entirely distinct root √kṣubh "to be agitated, to surge, to churn." Āniñjya (from √iñj, "to move/shake") and Akṣobhya (from √kṣubh, "to surge/agitate") are semantic near-synonyms ("immovable") but etymological non-cognates — different PIE derivations, different register of imperturbability. The discipline of noting this distinction carries over from the verification record (Patch 4).
Āniñjya (不動滅無為) is the fourth of six unconditioned dharmas (asaṃskṛta) in the Yogācāra 100-list. Asaṅga's Abhidharma-samuccaya gives the most precise definition: "the cessation of sukha specifically (sukha-nirodha) for one who has transcended the third-dhyāna level (śubhakṛtsna) but has not yet transcended desire for what lies above (upary-avītarāga)" — meaning: the practitioner established in the fourth dhyāna. The reasoning is precise: duḥkha (the gross suffering of the kāmadhātu) was abandoned at the first dhyāna; sukha (the bliss of the third dhyāna) is the most recently shed vedanā at the fourth dhyāna — so āniñjya names specifically this sukha-cessation as the distinguishing feature of the fourth dhyāna's imperturbability. 顯揚 and CWS both expand to "both sukha and duḥkha cessation" (苦樂受滅), which is also canonical — the standard four-dhyāna formula in both Pāli and Chinese Āgama traditions states that the fourth dhyāna involves abandonment of both pleasure and pain. Both readings are orthodox; Asg's is analytically sharper; 顯揚/CWS's is more pedagogically complete. The 百法 entry form is 「不動滅無為」 (with the 滅 character, per T31n1614_p0855c18) — the 滅 preserves the cessation character of āniñjya (it is the cessation of sukha-vedanā, not merely a state-name); 「不動無為」 is the common simplified variant but drops this precision. Within the Cheng Weishi Lun fascicle 2's five-aspect framework (「此五皆依真如假立」), āniñjya is the designation for dharma-nature viewed under the "cessation of pleasure-pain" (苦樂受滅) aspect — an aspect-naming on tathatā (#100), not a separately existing dharma substance. The prajñapti-sat mechanism: same as #95–#97 (→#95 for full framework), applied here to the dhyāna-quality of the fourth dhyāna.
The relationship to Theravāda at this entry is a categorial-architectural divergence (→ §4.8 for the architectural framework). The Pāli compound aneñjābhisaṅkhāra — the "imperturbable formation" — is cognate with Sanskrit āniñjya via shared root √iñj/ñj. Both terms point to the same phenomenology: the quality of unshakeability associated with the fourth jhāna and above. Yet Theravāda classifies aneñjābhisaṅkhāra as a conditioned formation (saṅkhāra-class, within the aggregate of saṅkhārakkhandha) — one of three types of volitional formations (meritorious / demeritorious / imperturbable; per SN 12.51, AN 4.171), arising from fourth-jhāna-and-above meditative activity, generating imperturbable rebirth in the formless realm. Yogācāra classifies the same imperturbability — the cessation of pleasure-pain vedanā at the fourth dhyāna — as an unconditioned dharma (asaṃskṛta, within the 無為 cluster). The Theravāda reasoning: imperturbable kamma-formations are conditioned precisely because they are formations (saṅkhāra) — they arise through intention, produce results, lead to rebirth in formless realms; their "imperturbability" is a quality of the resultant state, not an unconditioned dharma in its own right. The Yogācāra move: isolating the cessation aspect (of sukha-vedanā, of the movement of pleasure-pain) from the meditative event itself and designating that cessation-aspect as an imputation on tathatā — the «離繫性» (visaṃyoga) that obtains during fourth-dhyāna-level meditative stability. The divergence is not terminological but categorial-architectural: Theravāda says the imperturbability belongs to the conditioned aggregate (it is how kamma works at the fourth-jhāna level); Yogācāra says it also names an aspect of unconditioned dharma-nature (it is what tathatā looks like from the fourth-dhyāna vantage). Both traditions have the term; neither doubts the phenomenology; they disagree about which ontological register it belongs to.
The fourth dhyāna is where the practitioner first recognizes that pleasure itself (sukha) is a subtle form of restlessness — an object of grasping that has been refined but not abandoned in the third dhyāna. When sukha is relinquished (not suppressed, but seen through as a remaining movement), the quality that arises is captured in the term āniñjya: not-moving, not-swayed. Neither pleasure nor pain tilts the mind. The Pāli formula names this precisely: adukkhamasukha (neither-painful-nor-pleasant), accompanied by upekkhā (equanimity) and ekaggatā (one-pointedness). The CWS 卷二 phrase «苦、樂受滅，故名不動» names the dharma-nature aspect of this stability — the cessation of the pull of both vedanā-poles as a face of tathatā. The practitioner risk: mistaking the stillness of the fourth dhyāna for tathatā-realization. The stillness is āniñjya — an aspect-naming on dharma-nature, imputed on the cessation of the pleasure-pain movement. Tathatā (#100) itself is the principle of which āniñjya is one aspect; it is equally present when pleasure and pain are active, equally when they are stilled. The «not-moving» is a phenomenological achievement of the fourth dhyāna; the suchness of all dharmas (including those that move) is not a meditative achievement. The cluster-architecture makes this explicit: āniñjya is one of five aspect-namings on tathatā, not tathatā itself. The «immovability» that is worth cultivating is not this particular phenomenological still-point but the insight that movement and stillness alike arise within, and as aspects of, the one dharmatā (→#100 unifier).
Immovable cessation, the unconditioned (āniñjya, 不動滅無為) — designation upon the cessation of pleasure-vedanā (sukha-nirodha per Asg; sukha-and-duḥkha-vedanā cessation per 顯揚/CWS) attained at the threshold of the fourth dhyāna, by one who has transcended the third-dhyāna's bliss but not yet the formless realm's object. The imperturbability of the fourth dhyāna, named as an aspect of dharma-nature: not a separate substance, but a designation imputed on tathatā's «cessation-of-pleasure-pain» face. Fourth of the six unconditioneds; cluster-midpoint between the two analytic-cessation entries (#96–#97) and the deepest meditative cessation (#99). Pointing forward to tathatā (#100) as the unifier on which this and the four preceding asaṃskṛta-namings rest.
譯translator's note
譯者按： 結構分析詳 S3-P13。南傳 aneñjābhisaṅkhāra（不動業行）判為有為行蘊，北傳 āniñjya 立為無為假立；此結構性南北分判向上錨至 (→#100) 真如之無為架構（架構框架詳 §4.8）。