自足的人还要朋友干什么
Why Does the Self-Sufficient Person Need Friends?
第九卷第九章开头一句，是把一件有争的事摆出来：
幸福的人要不要朋友，这件事有争。
他不急着答，先把对面的话按原样摆足。
有福气又自足的人不需要朋友，因为好东西他都有了；既然自足，就不再缺什么；而朋友是另一个自己，朋友的用处是替你弄来你自己弄不来的东西。摆完他引了欧里庇得斯一句：运气好的时候，要朋友做什么。
摆得很足，足到像是他自己在说。
然后他回身。把一切好东西都给了幸福的人，偏不给他朋友，这看着说不过去；何况在身外的好东西里，朋友看来是最大的一样。
往下他先承认对面对了一半，而且指出对在哪儿。
那些先说话的人究竟在说什么，他们哪一点说对了。他自己答：多数人心里的朋友，指的是有用的那种。这一种，有福气的人一个也不需要，因为好东西他都有了。为着快活的那一种也不需要，或者只需要一点点，因为他的日子本来就是快活的，用不着从外头再搬进来。既然这两种都不需要，看上去他就是不需要朋友了。
"可这话大概不对。"
这一步是整章的关节。他不是把对面驳倒的。他是把对面说的那两种朋友一种一种承认掉，剩下的那一种才是他要谈的。
所以这一章从头到尾没有走"你缺什么，朋友替你补上"这条路。那条路是他自己拆掉的。
他那条路从一句旧话起：幸福是一种活动，而活动是做出来的，不是像一份家产那样搁在那儿的。
搁着的东西越多越自足；做出来的事情不这么算。
往下两步。一步是：我们看得清旁边的人，比看得清自己容易；看得清别人做的事，比看得清自己做的事容易。好人做的那些事，在同样是好人的朋友看来是快活的。
另一步更实：一个人独过，日子难。因为一个人自己一刻不停地做下去，不容易；跟别人一起，冲着别人，就容易些。这样那个活动才接得下去。
最后落到最深的一层。一个人看见的时候知道自己在看，听见的时候知道自己在听，走路的时候知道自己在走；照这样推下去，我们觉着的时候知道自己在觉，想的时候知道自己在想。而知道自己在觉在想，就是知道自己在着。
而朋友是另一个自己。所以对朋友的那一份，跟对自己的那一份，形状一样：知道他在着，跟知道自己在着，是同一种快活。
于是那一句才有内容：得一块儿觉着他在。这件事怎么才成，他说得很具体：一块儿过日子，共有话和想法。人说的一块儿过是这个意思，不是牲口在同一片地上吃草那个意思。
章末那一句因此毫不含糊：幸福的人，会需要好的朋友。
有人会把整章读成他在改自己的第一卷。
不是。第一卷定自足的时候他已经写明：自足不是指一个人自己过，是把父母妻子儿女朋友和同城的人一起算在内的。所以第九卷这一章不是他忘了再回头补，是他把第一卷早就排除过的那个读法重新请上桌，让它以最强的样子再问一遍。
话还得说全。第十卷讲那一样最高的活动的时候，他说有智慧的人一个人也做得了，越有智慧越做得了；有人一起做也许更好，可他还是最自足的那一个。这两处怎么合得起来，是他自己那一套里的一桩公案，本篇不判。摆在这儿，只为不让人以为他就说过一句。
他亲手拆掉的那条路，这边在同一个位置上也没有走。
《第一批判》里他者出场的那一处，写得很小心：自问担保不了发现自己的全部盲区，所以他者的追问提供一种自问没法自己担保的独立校验。紧跟着还有两句限：这不是说自问无效，也不是说他问是唯一的校验；把地址显式地维护住，另外设一道复核程序，各有各的用处。
这两句限一加，补缺口那条路在这边也走不通了。他者不是来把你少的那一块补上的。自问，把地址显式地记住，另设一道复核，这几样各有各的用处；而它们里头没有一样能替自问担保它自己的独立性。短的那一截不是内容，是那份独立。
一边把有用的朋友和图快活的朋友一种一种承认掉，一边把"另设一道复核也有用"明写在旁边。两边都不肯让他者站在补缺口那个位置上。
他把朋友安在日子里。这边把他者安在账上。
他把朋友放进"活着"这件事里。活动要接得下去，一个人接不下去；活动要看得见，看自己比看旁人难；而知道朋友在着，跟知道自己在着是同一种。他者进来的位置，是那个活动本身的条件。
这边把他者放进"算数"这件事里。一门哲学立起来，效力不由自家宣布，须经追问参与结算。他者进来的位置，是效力的结算。
一个说少的是那一段接得下去也看得见的活，一个说少的是那一道结算。
这两样在日子里分得很开。
一个人写完一份东西，自己读三遍，觉得没问题。这时候他要的是别人来挑错。这是结算那一头。
同一个人做完一件很久的事，一件他做得很好也确实做成了的事，他会想找个人说一声。不是要建议，也不是要夸。说完了那件事一分没变，可他还是要说。这是活着那一头。
两样谁也替不了谁。挑得出错的人不一定是能一块儿说话的人；能一块儿说话的人不一定挑得出错。
把这边调用过的几处他者接口一处一处点出来，就看得见少的是什么。
一处在幻相那一章：他问是自问担保不了的那一种校验。一处在发生那一章的最高一站：两个主体互相认对方是目的本身，那一站的否定不留下东西，留下的是对方的长。旁边还挨着一样叫涵育：让别人那条路能在不被人占去的条件下走下去，明写含着不去挡着和主动帮着两面。此外还有交叠里那一条共享的后验输入，说的是两条路在同一个世上，互相是对方的对象。
这几处能说明的是校验，是互认，是交叠，是替别人留出走得下去的条件。
没有一条把一块儿过日子本身算成好日子的一部分。
这句话得说准，它不是判这一整套里没有他者，也不是判这一整套里没有友爱可讲。它只判一件事：本篇调用的这几处，不给这一样。
而他给。他那一章收在一个判词上：不给他这个，他在这一处就有缺。
这个判词落得下来，是因为他先做过一件事：他把幸福定成活动，不是一份攒下的家当。定成活动，一段活动接不下去就是真的少了一段；缺口是可以算的。
这边这几处给的是校验的成色和越界的风险，不是好日子里有哪几样。要下他那个判词，得先有一个像他那样能算出缺口的量法。
这一笔不能算他多说了。是他先给了量法，判词才落得下来。
这边把一门哲学写成一本要外人来对的账，这一条站得住。
可账对完了，人还是想找个人说一声。
他那一章末了说的正是这件事：得一块儿觉着他在，而这件事得靠一块儿过日子，共有话和想法，不是牲口在同一片地上吃草。
账可以由别人来对。一块儿过日子算不算好日子的一部分，不在这本账里结。
The Friend Who Supplies Nothing Missing
If the happy person is self-sufficient, why would that person need friends? Aristotle opens Book IX, chapter 9 with the apparent contradiction. Someone who possesses the good lacks nothing, while a friend is often described as another self who supplies what one cannot provide alone.
Aristotle first removes two misleading cases. The supremely happy person does not need friends for utility, because the relevant goods are already present. Nor is friendship needed merely to import pleasure into an otherwise empty life. Happiness is already pleasant in itself.
The remaining friend is therefore not a repair service. The question is not what deficit the friend fills, but what kind of activity a good life is.
Happiness, Aristotle insists, is activity rather than a possession stored like property. A good person wants to exercise virtue, and it is easier to contemplate noble actions in a friend than in oneself. Activity with good companions is more continuous. The happy person also needs people toward whom generosity and beneficence can be exercised. A solitary life would be a strange assignment of every good except the goods of friendship.
Another Self, Not a Second Tool
Aristotle's argument deepens through consciousness. To perceive is also, in some sense, to perceive that one perceives; to think is to be aware that one thinks. For the good person, awareness of living and acting is pleasant because existence in such activity is good. A friend is another self, so the friend's existence is desirable in a related way.
Shared life then receives an exact meaning. Human beings do not live together merely by feeding in the same place, as cattle do. They share speech and thought. Friendship belongs to the very activity through which a human life becomes present to itself.
This is stronger than the claim that companionship is useful for well-being. The friend is internal to the exercise of the good life, though not a component owned by the happy person. Aristotle's self-sufficiency was never solitary autonomy; Book I had already included family, friends, and fellow citizens in its scope.
Book X complicates the picture. Contemplation is praised as the most self-sufficient activity because the philosopher can contemplate alone, at least more readily than the just person can exercise justice alone. The tension should not be hidden. Aristotle gives contemplation a special independence while still acknowledging that the philosopher, insofar as he is human and lives with others, chooses virtuous action and needs the conditions of human life.
The Other in SAE
SAE also refuses to make another person a device for completing the self. The other's importance appears in several forms: an independent challenge can disclose a blind spot; mutual recognition can establish a relation that self-declaration cannot produce alone; and cultivation can make room for another path without annexing it.
The center of gravity differs from Aristotle's. Aristotle asks what makes a flourishing life active, pleasant, and continuous. SAE asks what keeps a judgment from becoming self-authorizing and how accounts among persons are settled. The friend appears in one account as part of living well, in the other as a noncoincident subject whose answer affects validity.
This distinction matters. An auditor may be indispensable without being a friend. A friend may enrich a life without offering reliable review. Intimacy can even reduce independence when shared habits make the same premises invisible to both people. “Another person” is not one undifferentiated function.
What the Ledger Cannot Count
SAE is strongest when the issue is answerability. It can explain why a judgment about another person cannot be fully settled by the speaker alone, why consent cannot be manufactured from the claimant's side, and why self-audit cannot guarantee discovery of every blind spot. It is weaker at describing the positive good of sharing time.
Two friends walk, cook, repeat old jokes, or sit through an unremarkable afternoon. No dispute is settled. No premise is corrected. Nothing is added to a moral balance sheet, yet the life would be poorer without the time. Aristotle has a vocabulary for this: living together, sharing speech and thought, sustaining activity in company.
A theory organized around debts and review can acknowledge the fact without measuring it. But acknowledgment is not yet an account of why shared life belongs to flourishing. The ledger can be perfectly auditable and the person still want someone to tell.
Self-Sufficiency Without Solitude
The apparent paradox rests on a mistaken model of sufficiency. If self-sufficiency means possessing every needed resource inside an individual boundary, friendship must appear as evidence of lack. If it means a life choiceworthy and lacking nothing important, relations may belong within its form.
Aristotle does not solve every boundary problem. How many friends can one genuinely share life with? How do unequal dependence and political exclusion affect the ideal? His account of friendship is shaped by assumptions about citizenship and status that cannot simply be inherited. Yet the basic correction remains powerful: needing friends does not reduce them to remedies.
SAE adds another correction. The other is not valuable merely because my flourishing expands through relation. The other's independent position limits what I can authorize and completes some judgments in a way my own declaration cannot. This is not a richer possession for me; it is a boundary on me.
The two accounts therefore illuminate different dimensions. Aristotle explains why the good life does not become complete by becoming solitary. SAE explains why another subject cannot be absorbed into the self's account of that completeness.
The self-sufficient person needs friends not because something is missing from the warehouse, but because happiness is an activity and human activity is shared. And even after every account is balanced, a human life may still need a voice that is neither evidence nor instrument—only another person there to receive it.