唯識二十論 偈十九 夢覺果別
偈十八末對方抓漏洞：你老說夢與醒都是識起、都無外境，可夢裡殺人不會下地獄、醒著殺人要償命，同是識變沒外境，果報怎會差這麼多？這一問拿業報輕重逼問唯識。
世親只半句偈——「心由睡眠壞，夢覺果不同」，關鍵在「壞」字。夢裡的心被睡眠壞了、勢力羸弱昏沉；醒著的心勢力具足、清明有力。同一件惡行，由昏弱的夢心造和由清明的醒心造，造業的心力強弱本就天差地別，業的果報（異熟）有輕有重，差別正出在這「能造之心的力量」上，不在外境有沒有。對方本想用果報有別證外境有別，世親反手把果別歸到心力——業報輕重本來就該看心、不看外物，唯識反而說得更乾淨。
答完果別，對方換上最尖的一刀——殺生：若只有識、沒有身語等實在東西，「羊被屠夫殺死」怎麼成立？羊若不是被實實在在地傷害而死，屠夫憑什麼背殺生罪？這把唯識從思辨拉到倫理現場。世親不迴避也不在此偈答：把「無外境如何殺生」留給偈二十（他識轉變令命根斷），把「意業勝身語」留給偈二十一的佛問鄔波離經證。轉折要記住——對方想用果報之別證外境，世親卻證明：正因一切唯心，業報的輕重才看得這麼準。
At the end of Verse 18 the opponent seizes on a gap: you keep saying dream and waking are alike consciousness arising, alike without any external object — yet killing someone in a dream does not send you to hell, while killing someone awake costs you your life in return. Same consciousness-transformation, no external object either way — how can the fruit differ so greatly? The challenge presses consciousness-only with the gravity of karmic requital.
Vasubandhu's reply is only half a verse — "the mind is impaired by sleep; dream and waking differ in their fruit" — and the key is the word "impaired." The mind in a dream is impaired by sleep, its force feeble and torpid; the waking mind has its force intact, clear and strong. One and the same evil deed, done by a torpid dream-mind and by a clear waking mind — the strength or weakness of the very mental force that does the deed is worlds apart from the start. The fruit of the karma (its ripening, 異熟 vipāka) is light or heavy, and the difference arises precisely from this "force of the mind that does the deed," not from whether there is an external object. The opponent meant to use a difference in fruit to prove a difference in object; Vasubandhu turns it back and traces the difference in fruit to mental force — the lightness or heaviness of karmic requital was always to be measured by mind, not by outward things, and consciousness-only comes out the cleaner for it.
Having answered the difference in fruit, the opponent brings up the sharpest blade — taking life: if there is only consciousness and no real things such as body and speech, how is "a sheep killed by a butcher" established? If the sheep does not die by being really, actually harmed, on what grounds does the butcher bear the offence of taking life? This drags consciousness-only from speculation onto the ethical ground. Vasubandhu neither dodges nor answers within this verse: he leaves "how killing is possible with no external object" to Verse 20 (the life-faculty cut off by the transformation of another's consciousness), and "mental karma surpassing body and speech" to Verse 21's scriptural proof of the Buddha questioning Upāli. Remember the turn — the opponent wanted to use a difference in fruit to prove an external object, but Vasubandhu proves the reverse: it is precisely because all is mind-only that the lightness and heaviness of karmic requital can be measured so exactly.
§頌（半頌）
心由睡眠壞，夢覺果不同。
§論（世親自註）
論曰：在夢位心，由睡眠壞，勢力羸劣。覺心不爾，故所造行當受異熟，勝劣不同非由外境。若唯有識無身語等，羊等云何為他所殺？若羊等死不由他害，屠者云何得殺生罪？頌曰：
The canonical text stands in Chinese only. This edition renders the essence, the plain reading, the exposition and the apparatus into English — never the sūtra itself. Switch to 漢讀本 or 並行雙語 above to read it.
§頌 白話（半頌）
（夢裡的）心由於睡眠而被損壞（勢力衰弱）， 所以夢中和醒著（造業）的果報不相同。
§論 白話
世親解釋這首偈。
在作夢時候的心，由於睡眠而被損壞，勢力衰弱。醒著的心則不是這樣（勢力具足）。所以（夢中與醒著）所造的行為，將來要受的異熟（果報），就有勝、劣的不同——這並不是由於外境（造成的）。
（對方又難說：）如果只有識、沒有身體和言語等（實在的東西），那麼羊等怎麼會被別人殺死呢？如果羊等的死不是由於別人的傷害（而死），那麼屠夫又怎麼會得到「殺生」的罪呢？世親用下一首偈來回答。
§Verse — plain reading (half-verse)
The mind (in a dream) is impaired by sleep (its force grows weak), and so the fruit of deeds done dreaming and done awake is not the same.
§Auto-commentary — plain reading
Vasubandhu explains this verse.
The mind during a dream, being impaired by sleep, has weakened force. The waking mind is not like this (its force is intact). And so for the deeds done (in dream and awake), the ripening (異熟, vipāka) — the fruit that is to be received later — comes out superior or inferior, differing accordingly — and this is not on account of any external object.
(The opponent objects again:) if there is only consciousness and no body, speech, and the like (no real things), then how can a sheep and the like be killed by someone else? And if the death of a sheep and the like is not on account of being harmed by another, then how does the butcher come to incur the offence of "taking life"? Vasubandhu answers with the following verse.
接住偈十八末的那一問
偈十八末，對方抓住一個漏洞：你老說「夢與醒都是識起、都無外境」，可大家都知道——夢裡殺人不會下地獄，醒著殺人要償命。同樣是識變、同樣沒外境，果報怎麼會差這麼多？這一問挺實在：它拿「業報的輕重」來逼問唯識。
答案不在境，在「心力」
世親的回答只半句偈——「心由睡眠壞，夢覺果不同」。關鍵詞是「壞」。
夢裡的心，被睡眠「壞」了——勢力羸弱、模糊昏沉，像隔著一層；醒著的心則勢力具足、清明有力。同一件惡行，由一顆昏弱的夢心造，和由一顆清明的醒心造，造業的心力強弱本就天差地別。業的果報（異熟）有輕有重，差別正出在這「能造之心的力量」上——不在外境有沒有。
所以你看：果報之別，恰恰可以全用「心」來解釋，根本不需要搬出外境。對方本想用「果報有別」證明「外境有別」，世親反手一接，把果別歸到心力，唯識不但無礙，反而說得更乾淨——業報的輕重，本來就該看心，不看外物。
順勢逼出一個更硬的問題：殺生
答完果別，對方立刻換上最尖銳的一刀——殺生。他說：好，如果只有識、沒有身體和言語這些「實在的東西」，那「羊被屠夫殺死」這件事怎麼成立？羊若不是被屠夫實實在在地傷害而死，那屠夫又憑什麼背「殺生」的罪？
這一刀厲害，因為它把唯識從思辨拉到倫理現場：殺業是真的、殺罪是真的，你唯識若連「殺」都安立不了，豈不要崩？世親沒有迴避，但也不在這一偈答——他把「殺業如何在唯識中成立」留給偈二十（由「他識轉變」令命根斷），把更重的「意業勝於身語」留給偈二十一的經證。
承衍
偈十九做完兩件事：一是用「心力強弱」漂亮地解掉夢覺果別之難（果別在心不在境，唯識更顯）；二是引出 §肆 後段最硬的倫理難題——殺生。從這裡起，論辯從「認識」轉向「業與倫理」：偈二十答「無外境如何殺生」（他識轉變令命根斷），偈二十一更引佛問鄔波離的經證，立「意罰為大罪、心力勝身語」。讀偈十九，記住那個轉折——對方想用果報之別證外境，世親卻證明：正因為一切唯心，業報的輕重才看得這麼準。
Picking up the question left at the end of Verse 18
At the close of Verse 18 the opponent seizes on a gap: you keep saying "dream and waking alike are consciousness arising, alike without any external object" — yet everyone knows that killing someone in a dream does not send you to hell, while killing someone awake costs you your life in return. Same consciousness-transformation, same absence of an external object — how can the fruit differ so greatly? The challenge is a solid one: it presses consciousness-only with the gravity of karmic requital.
The answer is not in the object, but in "mental force"
Vasubandhu's reply is only half a verse — "the mind is impaired by sleep; dream and waking differ in their fruit." The key word is "impaired" (壞).
The mind in a dream is "impaired" by sleep — its force feeble, blurred and torpid, as though seen through a screen; the waking mind, by contrast, has its force intact, clear and strong. One and the same evil deed, committed by a torpid, weakened dream-mind, and committed by a clear, waking mind — the strength or weakness of the very mental force that does the deed is worlds apart from the start. The fruit of the karma, its ripening (異熟, vipāka), is light or heavy; and the difference arises precisely from this "force of the mind that does the deed" — not from whether there is an external object.
So you see: the difference in fruit can in fact be explained entirely by "mind," with no need at all to bring in an external object. The opponent meant to use "the fruit differs" to prove "the object differs"; Vasubandhu turns the move back, tracing the difference in fruit to mental force — and consciousness-only is not merely untroubled but comes out the cleaner for it: the lightness or heaviness of karmic requital was always to be measured by the mind, not by outward things.
Riding the momentum to force out a harder question: taking life
Having answered the difference in fruit, the opponent at once brings up the sharpest blade of all — taking life. He says: very well, if there is only consciousness and no "real things" such as body and speech, then how is the matter of "a sheep being killed by a butcher" to be established? If the sheep does not die by being really, actually harmed by the butcher, then on what grounds does the butcher bear the offence of "taking life"?
This blade is keen, because it drags consciousness-only out of speculation onto the ethical ground: the deed of killing is real, the offence of killing is real — if your consciousness-only cannot so much as establish "killing," does it not collapse? Vasubandhu does not dodge, but neither does he answer within this verse — he leaves "how the deed of killing is established under consciousness-only" to Verse 20 (the life-faculty is cut off by the "transformation of another's consciousness," 他識轉變), and the weightier point that "mental karma surpasses bodily and verbal karma" to the scriptural proof of Verse 21.
Carried forward (承衍)
Verse 19 does two things: first, it neatly dissolves the difficulty of the differing fruit of dream and waking by "the strength or weakness of mental force" (the difference in fruit lies in mind, not in object — consciousness-only shows the clearer for it); second, it leads out the hardest ethical problem of the latter part of §IV — taking life. From here on the debate turns from "cognition" toward "karma and ethics": Verse 20 answers "how killing is possible with no external object" (the life-faculty is cut off by the transformation of another's consciousness), and Verse 21 goes further, citing the scriptural proof of the Buddha's questioning of Upāli (鄔波離) to establish that "mental punishment is the great offence; mental force surpasses body and speech." In reading Verse 19, remember that turn — the opponent wanted to use the difference in fruit to prove an external object, but Vasubandhu proves the reverse: it is precisely because all is mind-only that the lightness and heaviness of karmic requital can be measured so exactly.
考據Apparatus
一、科判定位
| 系統 | 此偈之位 |
|---|---|
| 全論五段 | §肆 破現量·夢覺·教證（偈十五–廿一）之夢覺果別答偈（半頌）。偈十八懸「夢覺造行果別」之難 → 偈十九正答：夢心由睡眠壞、勢力羸劣，覺心不爾，故果有勝劣別，非由外境 ；末出殺生難（無身語則羊云何被殺）→ 偈二十 |
| 偈十八→偈十九 | 偈十八末問夢覺果何以不同；偈十九答以「心之勢力強弱」（夢心為眠所損），果別不待外境 |
| 玄奘段位 | §頌〔p0076c24〕（半頌）· §論自註〔p0076c25–28〕 |
二、源頌 · 義理脈絡
§頌半頌（二句）：「心由睡眠壞」（夢位之心為睡眠所壞、勢力羸劣）·「夢覺果不同」（故夢、覺所造業之果有別）。果別之因在「心力強弱」，不在外境之有無。
§論二節：(一)正答果別——夢位心由睡眠壞，勢力羸劣；覺心不爾。故所造行當受異熟有勝劣之別，非由外境。(二)引殺生難——若唯有識、無身語等，則羊等云何為他所殺？若羊不由他害而死，屠者云何得殺生罪？此難拶問「唯識如何安立殺業」，啟偈二十（他識轉變）。
三、經論宗依（經證 → 論本）
- 經證：業之異熟有勝劣、心力強弱影響業果，皆佛說業道之理；世親即以「夢心為眠所損」釋夢覺果別。
- 論本：世親自註（T1590）以「心之勢力強弱」立夢覺果別，並承殺生難；論之答，繫業道之心力義（非外境），不增不判。
四、本論釋要（世親自註 T1590）
本偈答偈十八末之夢覺果別難，鑰在心力：同是識起、同無外境，但夢中之心為睡眠所「壞」、勢力羸劣，覺時之心則勢力具足。心力既有強弱，所造善惡業之異熟自有勝劣之別——果之不同，源於能造之心力，非源於外境之有無。如是夢覺果別不礙唯識。論末對方轉一更尖之難：若唯識無身語，則「殺羊」這樣的事如何成立？羊若非被人所害而死，屠夫又如何得殺生之罪？此難把唯識逼向倫理現場——殺業、殺罪如何安立。世親引而未答，正面解在偈二十（由他識轉變令命根斷，殺業仍成）。本偈所涉「異熟·心力」皆佛法共傳之業道名相，論本就之立義，不增不判。
五、諸家異釋（古德 · 標宗）
- 護法《成唯識寶生論》T31n1591（唐·義淨譯·漢有傳本）——釋本偈，展開夢心羸劣、果別非外境及殺生難。〔標宗：護法於心力與業果處有詳釋；古德讀法之一，此處只記其宗，不判。〕
- Vinītadeva Prakaraṇaviṃśakaṭīkā——藏譯存·漢無傳本，依例僅志其名，內容不入義據。
六、譯名 · 古譯對讀（三漢譯）
| 漢譯 | 譯本 | 對讀 |
|---|---|---|
| ★ 唐·玄奘 T31n1590 | 「心由睡眠壞，夢覺果不同」（半頌） | 二句，以「心力強弱」答果別；自註引殺生難；以此為底本 |
| 陳·真諦 T31n1589《大乘唯識論》 | 散文連展夢覺果別與殺生難（古代漢證·參校） | |
| 後魏·般若流支 T31n1588《唯識論》 | 對應段以散文出之；逐字以 CBETA 為準（古代漢證·參校） |
七、術語（古德所傳梵 · 發音輔助）
| 漢 | 梵（發音輔助） | 義 |
|---|---|---|
| 異熟 | vipāka | 業之成熟果報；夢覺果別所在 |
| 勢力羸劣 | — | 心之勢力衰弱；夢心為睡眠所壞 |
| 命根 | jīvitendriya | 維繫一期生命之根；殺業所斷（詳偈二十） |
梵羅馬字僅作發音輔助；無古德音寫可徵者從闕，不據現代校本補。
八、互讀（唯識系次第）
| 百法明門論 | 唯識三十論 | 二十論內部 |
|---|---|---|
| #23 命根（不相應行）——殺業所斷之命根 ⭐ | 偈十九 異熟——業果勝劣由心力 | 偈十八 二識決定——本偈答其末懸之夢覺果別難 |
| #6 意識——造業之心；夢覺心力強弱 | 偈一「彼依識所變」——業果亦識變 | 偈二十 他識轉變——殺業由他識轉變令命根斷 |
| #8 阿賴耶識——異熟果之所依 | 偈二「異熟…思量…了境」——異熟識 | 偈廿一 意罰大罪——意業勝於身語 |
九、校本定位
- 漢文正文（§頌·半頌）：T31n1590〔p0076c24〕（玄奘譯）
- 漢文自註（§論）：T31n1590〔p0076c25–28〕（玄奘譯）
- 參校漢譯：T31n1589（真諦《大乘唯識論》）· T31n1588（般若流支《唯識論》）
- 古德釋：T31n1591（護法《成唯識寶生論》·漢有傳本）
1. Doctrinal-outline placement
| System | This verse's place |
|---|---|
| The treatise's five parts | The dream-and-waking-differing-fruit answer-verse (a half-verse) of §IV Refuting [the appeal to] Direct Perception · Dream-and-Waking · Scriptural Proof (vv.15–21). Verse 18 leaves hanging the objection of 「夢覺造行果別」 ("the differing fruit of deeds done dreaming and awake") → v.19 answers directly: the dream-mind is impaired by sleep and its force is feeble, the waking mind is not so; hence the fruit differs as superior or inferior, not on account of an external object; at its close it issues the taking-life objection (with no body and speech, how is a sheep killed) → v.20 |
| v.18 → v.19 | The end of v.18 asks why the fruit of dream and waking differs; v.19 answers by "the strength or weakness of the mind's force" (the dream-mind being impaired by sleep) — the difference in fruit needs no external object |
| Xuanzang's textual loci | §Verse 〔p0076c24〕 (half-verse) · §Auto-commentary 〔p0076c25–28〕 |
2. The source-verse · the doctrinal thread
The §Verse half-verse (two lines): 「心由睡眠壞」 ("the mind is impaired by sleep" — the mind in the dream-state is impaired by sleep, its force feeble) · 「夢覺果不同」 ("dream and waking differ in their fruit" — hence the fruit of the karma done in dream and in waking differs). The cause of the difference in fruit lies in "the strength or weakness of mental force," not in the presence or absence of an external object.
The §Auto-commentary has two parts: (i) the direct answer on the difference in fruit — the mind in the dream-state is impaired by sleep, its force feeble; the waking mind is not so. And so the deeds done are to receive a ripening that differs as superior or inferior, not on account of an external object. (ii) introducing the taking-life objection — if there is only consciousness and no body, speech, and the like, then how can a sheep and the like be killed by another? And if the sheep does not die by being harmed by another, how does the butcher come to incur the offence of taking life? This objection presses the question "how does consciousness-only establish the deed of killing," opening to v.20 (the transformation of another's consciousness, 他識轉變).
3. Scripture and treatise: the grounding (scriptural proof → treatise-root)
- Scriptural proof. That the ripening (異熟, vipāka) of karma is superior or inferior, and that the strength or weakness of mental force affects the karmic fruit, are alike the Buddha's teaching on the way of karma (業道); Vasubandhu accordingly explains the differing fruit of dream and waking by "the dream-mind being impaired by sleep."
- Treatise-root. Vasubandhu's auto-commentary (T1590) establishes the differing fruit of dream and waking by "the strength or weakness of the mind's force," and takes up the taking-life objection; the treatise's answer is tied to the karmic-path principle of mental force (not to an external object), adding nothing and adjudicating nothing.
4. The treatise-root in essence (Vasubandhu's auto-commentary, T1590)
This verse answers the dream-and-waking-differing-fruit objection left at the end of v.18; the key is mental force (心力): consciousness arises alike and there is alike no external object, but the mind in a dream is "impaired" (壞) by sleep, its force feeble, while the mind in waking has its force intact. Since mental force has its strength and weakness, the ripening of the good or evil karma done has of itself a difference of superior and inferior — the difference in fruit arises from the force of the mind that does the deed, not from the presence or absence of an external object. Thus the differing fruit of dream and waking is no obstacle to consciousness-only. At the close of the commentary the opponent turns to a sharper objection: if consciousness-only has no body and speech, how is such a thing as "killing a sheep" established? If the sheep does not die by being harmed by a person, how does the butcher come to incur the offence of taking life? This objection drives consciousness-only onto the ethical ground — how the deed of killing and the offence of killing are established. Vasubandhu introduces it but does not answer it [here]; the direct resolution is in v.20 (the life-faculty is cut off by the transformation of another's consciousness, and the deed of killing still holds). The "ripening · mental force" (異熟·心力) touched on in this verse are all karmic-path technical terms commonly transmitted in the Dharma; the treatise-root establishes its meaning upon them, adding nothing and adjudicating nothing.
5. The ancient masters' readings (古德 · stating their position)
- Dharmapāla, Cheng weishi baosheng lun 《成唯識寶生論》T31n1591 (Tang; tr. Yijing 義淨; a transmitted Chinese witness) — expounds this verse, unfolding the dream-mind's feebleness, the difference in fruit not [being] from an external object, and the taking-life objection. 〔Position stated: Dharmapāla gives a detailed exposition at the point of mental force and the karmic fruit; this is one of the ancient masters' readings, recorded here only as to its position, not adjudicated.〕
- Vinītadeva, Prakaraṇaviṃśakaṭīkā — extant in Tibetan translation · no transmitted Chinese witness; per convention its name only is recorded, its content not entering as doctrinal ground.
6. Rendering and old-translation comparison (the three Chinese translations)
| Chinese translation | Edition | Comparison |
|---|---|---|
| ★ Tang · Xuanzang T31n1590 | 「心由睡眠壞，夢覺果不同」 (half-verse) | Two lines, answering the difference in fruit by "the strength or weakness of mental force"; the auto-commentary introduces the taking-life objection; this is taken as the base text |
| Chen · Paramārtha T31n1589 《大乘唯識論》 | Sets out the differing fruit of dream and waking and the taking-life objection continuously in prose (an ancient Chinese witness · collated for comparison) | |
| Later Wei · Prajñāruci T31n1588 《唯識論》 | The corresponding passage is given in prose; the verbatim follows the CBETA [original] (an ancient Chinese witness · collated for comparison) |
Verbatim comparison follows the CBETA original text; what has not been verified against the original is not recorded verbatim.
7. Terms (Sanskrit per the ancient transmission · pronunciation aid)
| Chinese | Sanskrit (pronunciation aid) | Sense |
|---|---|---|
| 異熟 | vipāka | the matured fruit of karma; where the differing fruit of dream and waking lies |
| 勢力羸劣 | — | the mind's force weakened; the dream-mind impaired by sleep |
| 命根 | jīvitendriya | the faculty sustaining one term of life; what the deed of killing cuts off (detailed in v.20) |
The Sanskrit roman script is a pronunciation aid only; where no ancient-master transliteration is attested, it is left blank, not supplied from modern critical editions.
8. Cross-reading (the Yogācāra sequence)
| Baifa (Hundred Dharmas) | Triṃśikā | Within the Viṃśatikā |
|---|---|---|
| #23 the life-faculty (命根, a conditioned factor not concurrent [with mind]) — the life-faculty cut off by the deed of killing ⭐ | Triṃśikā v.19 ripening (異熟) — the karmic fruit, superior or inferior, by mental force | v.18 the determinacy of two consciousnesses (二識決定) — this verse answers the dream-and-waking-differing-fruit objection left hanging at its close |
| #6 mind-consciousness (意識) — the mind that does the deed; the strength or weakness of mental force in dream and waking | Triṃśikā v.1 「彼依識所變」 ("that rests on consciousness-transformation") — the karmic fruit too is consciousness-transformation | v.20 the transformation of another's consciousness (他識轉變) — the deed of killing cuts off the life-faculty by the transformation of another's consciousness |
| #8 storehouse consciousness (阿賴耶識) — that on which the ripened fruit rests | Triṃśikā v.2 「異熟…思量…了境」 ("ripening… deliberating… cognizing the object") — the ripening consciousness | v.21 mental punishment the great offence (意罰大罪) — mental karma surpasses body and speech |
9. Witness placement
- Chinese verse-text (§Verse · half-verse): T31n1590 〔p0076c24〕 (Xuanzang)
- Chinese auto-commentary (§Auto-commentary): T31n1590 〔p0076c25–28〕 (Xuanzang)
- Chinese translations collated for comparison: T31n1589 (Paramārtha, 《大乘唯識論》) · T31n1588 (Prajñāruci, 《唯識論》) — verbatim comparison follows the CBETA original text
- Ancient master's commentary: T31n1591 (Dharmapāla, 《成唯識寶生論》 · a transmitted Chinese witness)