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第 3 期 · 回应 Ⅱ·01「知识从哪里来？」
CRITICAL THINKING - Fundamentals: Introduction to Critical Thinking [HD]
节目发布 2014-08-01 · Wireless Philosophy章节 · 点击跳转视频
0:00
课程概览与批判性思维的定义
0:41
派对案例：三种理由的优劣
1:42
「好理由」的含义：与道德无关，与真相关
2:40
理性人为何需要批判性思维
2:40
什么是论证：前提与结论
4:09
红色与紫色论证：相关性决定好坏
5:08
背景前提如何改写论证的评价
5:41
演绎论证：前提保证结论
7:06
扩展性论证：前提使结论很可能
7:35
先判断论证类型，再选择评估工具
8:33
本课总结
本期讲者
杰夫·平恩北伊利诺伊大学哲学系教师，研究方向为知识论。他是 Wireless Philosophy（Wi-Phi）「批判性思维基础」系列课程的主讲人之一，本视频为该系列第一讲。
01课程概览与批判性思维的定义
0:00
(intro music) I'm Geoff Pynn. I teach at Northern Illinois University, and this is an introduction[br]to critical thinking. In this lesson, we're gonna[br]talk about three things. First, what is critical thinking? Second, what is an argument? And third, what's the difference between deductive and ampliative arguments? Okay, so what is critical thinking? Well, fundamentally, critical thinking is about making sure that you have good reasons for your beliefs. What does that mean? So suppose that you and your friend are talking about who's[br]gonna be at tonight's party.
（片头音乐）我是 Geoff Pynn，任教于北伊利诺伊大学，这是一门批判性思维入门课。这节课我们要讲三件事。第一，什么是批判性思维？第二，什么是论证？第三，演绎论证和扩展性论证（ampliative arguments）有什么区别？好，那么什么是批判性思维呢？从根本上说，批判性思维就是要确保你的信念有充分的理由。这是什么意思呢？假设你和朋友在聊今晚的派对上会有谁来。
02派对案例：三种理由的优劣
0:41
And she says to you, quite confidently, "Monty won't be at the party." You're not sure whether[br]or not to believe her, so it would be natural[br]for you to follow up by asking, "Why do you think so?" And there are a lot of different things that she might say in response. We're gonna talk about three possible answers she could give. First, she might say, "I can't stand him, and I want to have a good time." Second, she might say,[br]"Well, he's really shy, and he rarely goes to parties." And third, she might say, "He's in Beijing, and it's impossible to get here from[br]Beijing in an afternoon."
她非常肯定地对你说：“Monty 不会来这个派对。”你不确定该不该相信她，所以你很自然地会追问一句：“你为什么这么认为？”她可能会给出很多种不同的回答。我们来讨论她可能给出的三种回答。第一种，她可能说：“我受不了他，我想玩得开心点。”第二种，她可能说：“他非常害羞，很少去参加派对。”第三种，她可能说：“他在北京，而一个下午之内根本不可能从北京赶到这里。”
1:14
The first response that she gives you does not give you a good reason to believe that Monty won't be at the party. The second reason,[br]though, is a good reason to believe that Monty[br]won't be at the party. If he's really shy and[br]rarely goes to parties, then it's probable that he[br]won't be at tonight's party. Similarly, the third reason[br]also gives you a good reason to believe that[br]Monty won't be at the party. If he's in Beijing, and[br]it's impossible to get here from Beijing in an afternoon,[br]then it's guaranteed that he won't be at the party.
她给出的第一个回答，并没有给你一个好理由去相信 Monty 不会来派对。不过第二个理由，确实是一个相信 Monty 不会来派对的好理由。如果他非常害羞、很少去参加派对，那么他很可能不会出现在今晚的派对上。同样，第三个理由也给了你一个好理由，去相信 Monty 不会来派对。如果他人在北京，而一个下午之内不可能从北京赶到这里，那就可以肯定他不会出现在派对上。
03「好理由」的含义：与道德无关，与真相关
1:42
And when you notice things like that, when you distinguish between good and bad reasons for believing something, you're exercising your[br]critical thinking skills. So critical thinking is making sure we have good reasons for our beliefs, and so one of the essential[br]skills that you learn when you're studying[br]critical thinking is how to distinguish good reasons[br]for believing something from bad reasons for believing something. Now, it's worth saying something about how I'm using the term "good" here.
当你注意到这类差别，当你能区分相信某件事的好理由和坏理由时，你就是在运用你的批判性思维能力。所以，批判性思维就是确保我们的信念有充分的理由，因此，学习批判性思维时你要掌握的一项核心技能，就是如何把相信某事的好理由和相信某事的坏理由区分开来。另外，有必要说明一下我在这里是怎么使用“好”这个词的。
2:08
I'm not using it to indicate anything having to do with morality or ethics. So it's not morally right or morally good to believe something on[br]the basis of good reasons. Similarly, it's not morally[br]wrong, or evil, or wicked to believe something on[br]the basis of a bad reason. Rather, here, what it is to[br]say that a reason is good is closely tied to the notion of truth. So a good reason for a belief is one that makes it probable, that is, it's one that makes the belief likely to be true. The very best reasons for a belief make it certain, they guarantee it.
我用它并不是指任何跟道德或伦理有关的东西。所以，基于好理由去相信某件事，并不是说这在道德上是正确的或道德上是好的。同样地，基于一个糟糕的理由去相信某件事，在道德上并不算错误、邪恶或恶劣。更确切地说，在这里，说一个理由是好理由，是与'真'这个概念密切相关的。所以，一个支持某个信念的好理由，就是能让这个信念变得可能成立的理由，也就是说，它让这个信念很可能为真。支持一个信念的最好的理由能让它变得确定无疑，能够保证它为真。
05什么是论证：前提与结论
2:40
So why does this matter? Well, the reason that critical thinking is important is because,[br]since we're rational, we want our beliefs to be true. Rational people want to have true beliefs, and they want not to have false beliefs. And the best way to be[br]rational in this way is to form beliefs only when you find good reasons for them. Okay, that leads us to[br]our second question: What is an argument? Well, an argument is a set[br]of statements that together comprise a reason for a further statement.
那么这为什么重要呢？嗯，批判性思维之所以重要，是因为既然我们是理性的，我们就希望自己的信念是真的。理性的人希望持有真信念，并且不希望持有假信念。而要在这方面做到理性，最好的办法就是：只在你找到好理由的时候才形成信念。好，这就引出了我们的第二个问题：什么是论证？论证是一组陈述，它们合在一起构成了支持另一个陈述的理由。
3:09
So, for example, we can consider one of your friend's responses[br]before as an argument. She's given you two statements, "Monty's really shy" and[br]"Monty rarely goes to parties," which together comprise[br]a reason for believing that Monty won't be at the party. The statements that are the reason, we call the argument's premises. So "Monty's really shy" is premise one, "Monty rarely goes to[br]parties" is premise two, and the statement that[br]those premises give you reason to believe, we call[br]the argument's conclusion.
举个例子，我们可以把你朋友之前的一个回答看作一个论证。她给了你两个陈述：'Monty 真的很害羞'和'Monty 很少去参加聚会'，这两句话合起来构成了相信'Monty 不会来聚会'的理由。作为理由的那些陈述，我们称之为论证的前提。所以'Monty 真的很害羞'是前提一，'Monty 很少去参加聚会'是前提二，而这些前提让你有理由去相信的那个陈述，我们称之为论证的结论。
3:40
A good argument is one[br]in which the premises give you a good reason for[br]the conclusion, that is, the premises make the[br]conclusion likely to be true. In that case, we say that the argument supports the conclusion. Good arguments support their conclusions, and bad arguments don't[br]support their conclusions. So a key part of critical[br]thinking is learning to evaluate arguments to determine whether or not they're good or bad, that is, whether or not their premises support their conclusions.
好论证就是前提为结论提供了好理由的论证，也就是说，前提使得结论很可能为真。在这种情况下，我们就说这个论证支持该结论。好论证支持它们的结论，坏论证则不支持它们的结论。所以批判性思维的一个关键部分，就是学会评估论证，判断它们是好是坏，也就是说，判断它们的前提是否支持其结论。
06红色与紫色论证：相关性决定好坏
4:09
The red argument is the first response that she gave, two premises, "I can't stand Monty" and "I[br]want to have a good time." And the conclusion is "Monty[br]won't be at the party." And the third argument,[br]which we'll put in purple, consisted also of two premises, "Monty's in Beijing" and[br]"He can't get from Beijing to the party in time, so[br]he won't be at the party." Now, as I indicated[br]before, the first argument is not good, while the[br]purple argument is good. And here I can explain a[br]little bit more about why.
红色的这个论证是她给出的第一个回答，有两个前提：'我受不了 Monty'和'我想玩得开心'。而结论是'Monty 不会来聚会'。第三个论证，我们用紫色标出，同样包含两个前提：'Monty 在北京'和'他没法从北京及时赶到聚会，所以他不会出现在聚会上'。正如我之前指出的，第一个论证不是好论证，而紫色的论证是好论证。在这里我可以更详细地解释一下原因。
4:40
If you consider what the[br]red argument's premises say, that your friend can't stand Monty, and she wants to have a good time, and think about their relationship to the conclusion of the argument, you'll see that those[br]statements don't make that conclusion any[br]more likely to be true. The fact that your[br]friend can't stand Monty and wants to have a good[br]time doesn't do anything to make it more likely[br]that Monty won't be there. It's simply unrelated to the conclusion. In the purple argument,[br]though, the premises, if they're true, they guarantee[br]the conclusion is true.
如果你想想红色论证的前提说了什么——你朋友受不了 Monty，而且她想玩得开心——再想想它们与该论证结论之间的关系，你就会发现，这些陈述并没有让那个结论变得更有可能为真。你朋友受不了 Monty 并且想玩得开心，这个事实丝毫没有让'Monty 不会去'这件事变得更有可能。它跟结论根本毫无关系。而在紫色论证里，前提如果为真，就保证了结论为真。
07背景前提如何改写论证的评价
5:08
So they make it very probable. The truth of the premises[br]guarantees the truth of the conclusion, and so[br]in the purple argument, the premises do support the conclusion. Now, it's worth pointing[br]out that the red argument, though it's bad as it[br]stands, could be made a good argument with the addition of some background premise. So, for example, if you found out that your friend was[br]the person who decided who was going to be invited to the party, then the fact that she can't stand Monty and wants to have a good time would give you a good reason to believe that Monty won't be at the party, because it would give you reason to believe that she didn't invite him.
所以它们让结论的可能性非常高。前提为真就保证了结论为真，因此在紫色论证中，前提确实支持结论。不过值得指出的是，红色论证虽然就目前这个样子来说是坏论证，但如果加上某个背景前提，它是可以变成好论证的。比如说，如果你发现你朋友正是决定邀请谁来聚会的那个人，那么她受不了 Monty 又想玩得开心这个事实，就会给你一个相信 Monty 不会来聚会的好理由，因为这会让你有理由相信她没有邀请他。
08演绎论证：前提保证结论
5:41
But as it stands, the[br]argument is not good. Those two premises[br]considered in themselves give you no reason to believe that Monty won't be at the party. Okay, our last topic is to distinguish two different types of arguments. So I'm gonna put up here, on the left, the orange argument, which is the second response that your friend gave, "Monty's really shy" and[br]"He rarely goes to parties." On the right we'll put[br]the purple argument, "Monty's in Beijing" and "He can't get from Beijing[br]to the party in time."
但就目前这个样子来说，这个论证不是好论证。单就这两个前提本身而言，它们并没有给你任何理由去相信 Monty 不会来聚会。好，我们最后一个话题是区分两种不同类型的论证。我在左边放上橙色的论证，也就是你朋友给出的第二个回答：'Monty 真的很害羞'和'他很少去参加聚会'。右边我们放紫色的论证：'Monty 在北京'和'他没法从北京及时赶到聚会'。
6:06
Both of them have the same conclusion, "Monty won't be at the party." Now, as I said before, both of these are good arguments, they both do give you reason to believe the conclusion, i.e., both of them have premises which support the conclusion, but there's an important difference between the two arguments[br]that I want to point out. If you consider the purple argument, and think about what those premises say, you'll notice that if[br]those premises are true, if Monty's in Beijing,[br]and can't get from Beijing to the party in time, then it must be true that Monty won't be at the party.
两者的结论是一样的：'Monty 不会来聚会'。正如我之前所说，这两个都是好论证，它们都确实给了你相信该结论的理由，也就是说，两者的前提都支持结论，但这两个论证之间有一个重要的区别，我想指出来。如果你思考一下紫色论证，想想那些前提说了什么，你会注意到，如果这些前提为真，如果 Monty 在北京，而且没法从北京及时赶到聚会，那么就必然为真：Monty 不会来聚会。
6:34
Those premises guarantee the conclusion. In such an argument, where the premises guarantee the truth of the conclusion, we call the argument deductive. In a deductive argument,[br]given the premises, the conclusion must be true. Just thinking about the information in the premises in a deductive argument gives you all you need[br]to deduce the conclusion. If you look at the[br]orange argument, though, you'll notice that that's not the case. In the orange argument,[br]even if those premises are true, the conclusion[br]might still be false.
这些前提保证了结论成立。在这样一种前提保证结论为真的论证中，我们称该论证为演绎论证。在演绎论证中，只要给定前提，结论就必然为真。在演绎论证里，只要思考前提中包含的信息，就足以让你推演出结论。但如果你看看橙色的论证，你会注意到情况并非如此。在橙色论证中，即使那些前提为真，结论仍然可能是假的。
09扩展性论证：前提使结论很可能
7:06
Even given that Monty is really shy and rarely goes to parties,[br]it's still possible that he'll get over[br]his shyness and suspend his policy of rarely going to parties, and unexpectedly show up. It's unlikely, but it's possible. So the truth of the premises[br]in the orange argument does not guarantee the[br]truth of the conclusion. Arguments like this, we call ampliative. In an ampliative argument,[br]the truth of the premises makes the conclusion probable[br]but doesn't guarantee it. Now, as I said, both of[br]the arguments are good.
即便 Monty 确实很害羞而且很少去参加聚会，他仍然有可能克服自己的害羞，暂时打破他很少去聚会的惯例，出人意料地出现。这不太可能，但确实有可能。所以在橙色论证中，前提为真并不保证结论为真。这样的论证，我们称之为扩展性论证（ampliative）。在扩展性论证中，前提为真使结论变得很可能，但并不保证结论成立。如我所说，这两个论证都是好论证。
10先判断论证类型，再选择评估工具
7:35
Ampliative arguments can often be very good arguments,[br]they're just not deductive. The premises don't guarantee[br]the truth of the conclusion. Now, when you're evaluating an argument, it can be important to know whether or not the argument is supposed to be deductive or supposed to be merely ampliative. If an argument is[br]supposed to be deductive, but careful consideration of the argument reveals that in fact the premises don't guarantee the[br]truth of the conclusion, if the conclusion could[br]be false even though the premises are true,[br]that's often a good reason to reject the argument as a bad argument.
扩展性论证往往可以是非常好的论证，只不过它们不是演绎的。前提并不保证结论为真。那么，当你在评估一个论证时，弄清楚这个论证是打算作为演绎论证，还是仅仅打算作为扩展性论证，可能是很重要的。如果一个论证本应是演绎的，但仔细审视后发现，实际上前提并不保证结论为真，如果前提为真而结论仍可能为假，那这通常就是一个好理由，让你把这个论证判定为坏论证而加以拒斥。
8:06
Whereas in an ampliative argument, to notice that the truth of the premises doesn't guarantee the[br]truth of the conclusion, is simply to notice that[br]it's an ampliative argument. If you were to object[br]to the orange argument by pointing out that,[br]still, the conclusion could be false, you'd[br]really be missing the point. In an ampliative argument,[br]it's taken for granted that the conclusion is not[br]guaranteed by the premises. Rather, what an ampliative[br]argument is doing is giving you reasons to think that the conclusion is probable.
而在扩展性论证中，注意到前提为真并不保证结论为真，不过是注意到它是一个扩展性论证罢了。如果你反驳橙色论证的方式是指出：结论毕竟还是可能为假，那你其实就没抓住重点。在扩展性论证中，'结论并不由前提所保证'本来就是被默认接受的前提。扩展性论证所做的事情，是给你一些理由去认为结论很可能成立。
11本课总结
8:33
So knowing what type of[br]argument an argument is is essential to knowing which tools to use to evaluate whether or[br]not it's a good argument. And we'll talk quite a bit more about different tools for[br]evaluating both ampliative and deductive arguments in future lessons. Okay, so summing up this lesson. Critical thinking is making sure that we have good reasons for our beliefs, where we understand a good reason as one that makes the belief[br]probable, or likely to be true. An argument is a set of statements, which we call premises,[br]that together comprise a reason for another statement, which we call the argument's conclusion.
所以，知道一个论证属于哪种类型，对于知道该用哪些工具来评估它是不是好论证，是至关重要的。在以后的课程中，我们会更多地讨论评估扩展性论证和演绎论证的各种不同工具。好，我们来总结一下这节课。批判性思维就是确保我们对自己的信念持有好理由，而我们把好理由理解为：使该信念变得很可能、或很可能为真的理由。论证是一组陈述——我们称之为前提——它们合起来构成了支持另一个陈述的理由，那个陈述我们称之为论证的结论。
9:08
And in a good argument, the premises support their conclusions, that is, the premises give you a[br]good reason for believing the conclusion, because[br]they make it probable. A deductive argument is[br]one where the conclusion is guaranteed by the premises.[br]If the premises are true, then the conclusion must be true. An ampliative argument[br]is one where the premises don't guarantee the conclusion, but they do make it probable. So they can still provide you with good reason for[br]believing the conclusion.
而在一个好论证中，前提支持其结论，也就是说，前提给了你相信该结论的好理由，因为它们使该结论变得很可能。演绎论证是结论由前提所保证的论证。如果前提为真，那么结论就必然为真。扩展性论证则是前提并不保证结论的论证，但它们确实使结论变得很可能。所以它们仍然能为你提供相信该结论的好理由。
9:37
Okay, so that ends this[br]introductory lesson.
好，这节入门课就到这里。
9:47
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视频总结 · 一句话概括与核心要点
本视频是 Wireless Philosophy「批判性思维基础」系列的第一讲，由北伊利诺伊大学哲学教师 Geoff Pynn 主讲，回答三个问题：什么是批判性思维、什么是论证、演绎论证与扩展性论证有何区别。
定义与动机。 讲者把批判性思维定义为「确保信念有好理由」，并用朋友断言「Monty 不会来派对」的三种解释做贯穿案例：个人好恶、性格习惯、身在北京。他随即澄清「好」是认识论意义而非道德意义——好理由使信念很可能为真，最好的理由能保证其为真；理性人追求真信念，所以只应在有好理由时形成信念。
论证的结构。 论证是一组陈述（前提）共同构成支持另一陈述（结论）的理由。好论证即前提使结论很可能为真。「讨厌 Monty」的红色论证之所以失败，是因为前提与结论不相关；但若补上「她决定邀请名单」这一背景前提，它就能变成好论证——论证评价依赖隐含前提。
两类论证。 关键转折在于区分「保证」与「很可能」：紫色论证（在北京）前提为真则结论必真，是演绎论证；橙色论证（害羞）前提为真结论仍可能为假，是扩展性论证。二者都是好论证。评估时须先判断论证意图属于哪类：对演绎论证，一个反例即可推翻；对扩展性论证，指出「结论可能为假」则是没抓住重点。课程以三个定义的复述收束，并预告后续将介绍针对两类论证的不同评估工具。
核心句型 · 9
1. It would be natural for sb. to do …
“It would be natural for you to follow up by asking, "Why do you think so?"”
用 it would be natural for + 人 + to do 表示「某人自然会……」，语气委婉，适合描述合理的反应或预期行为。仿写：It would be natural for readers to wonder why.
2. X gives you a good reason to believe that …
“The third reason also gives you a good reason to believe that Monty won't be at the party.”
论证类写作的核心表达，说明某证据支持某结论。可替换为 provides / offers grounds to believe。否定形式：does not give you any reason to believe。
3. It's worth saying / pointing out something about …
“It's worth saying something about how I'm using the term "good" here.”
用于插入说明或补充澄清，常见于讲课和学术写作。后接名词或 how/why 从句。类似表达：It's worth noting that…
4. Rather, what X is doing is …
“Rather, what an ampliative argument is doing is giving you reasons to think that the conclusion is probable.”
先否定一种理解，再用 rather + what … is doing is 引出正确理解。强调句结构，突出「真正在做的事」。适合纠正误解。
5. If A, then it must be true that B.
“If Monty's in Beijing, and can't get from Beijing to the party in time, then it must be true that Monty won't be at the party.”
表达必然推论的条件句。must be true that 强调逻辑必然性，比 will 更强。用于说明演绎关系或不可避免的后果。
6. as it stands
“The red argument, though it's bad as it stands, could be made a good argument with the addition of …”
「就目前的状况来说」，常与 though / but 搭配，先承认现状再提出改进可能。仿写：The draft, as it stands, needs more evidence.
7. It's unlikely, but it's possible.
“It's unlikely, but it's possible.”
短句对比结构，先让步再强调可能性。适合在论证中承认小概率反例。也可写作 Improbable, yes—but not impossible.
8. If you were to object to X by …, you'd really be missing the point.
“If you were to object to the orange argument by pointing out that, still, the conclusion could be false, you'd really be missing the point.”
虚拟语气 if you were to … you'd … 用于假设某种反驳并指出其不当。missing the point 是地道说法，指没抓住要害。
9. Knowing X is essential to knowing Y.
“Knowing what type of argument an argument is essential to knowing which tools to use”
动名词作主语，表达「知道 X 是知道 Y 的前提」。注意原文 is is 是动名词短语主语后接系动词的正常现象。
生词精讲 · 51 · 按出现顺序
ampliative
/ˈæmplɪˌeɪtɪv/
adj.
0:00
扩展性的（逻辑学术语，指结论内容超出前提的论证，约等于归纳论证）
deductive
/dɪˈdʌktɪv/
adj.
0:00
演绎的（前提为真则结论必然为真）
fundamentally
/ˌfʌndəˈmentəli/
adv.
0:00
从根本上说；本质上
quite confidently
phr.
0:41
相当肯定地、很有把握地（说）
follow up
phr. v.
0:41
追问；接着进一步询问或采取行动
can't stand
phr.
0:41
受不了、极其讨厌（某人/某事）
probable
/ˈprɑːbəbəl/
adj.
1:14
很可能的；有较大概率的（比 possible 程度高）
guaranteed
/ˌɡærənˈtiːd/
adj.
1:14
有保证的、确定无疑的
distinguish between
phr.
1:42
区分、辨别（A 与 B）
exercising
/ˈeksərsaɪzɪŋ/
v.
1:42
运用、行使（能力、权利）；此处非「锻炼」义
it's worth saying something about
phr.
1:42
有必要说明一下……；值得谈谈……
morality
/məˈræləti/
n.
2:08
道德；道德准则
ethics
/ˈeθɪks/
n.
2:08
伦理学；伦理
on the basis of
phr.
2:08
基于、根据……
wicked
/ˈwɪkɪd/
adj.
2:08
邪恶的、恶劣的
closely tied to
phr.
2:08
与……密切相关、紧密联系
the notion of
phr.
2:08
……的概念、观念
rational
/ˈræʃənəl/
adj.
2:40
理性的；合乎理性的
comprise
/kəmˈpraɪz/
v.
2:40
构成、组成（此处 comprise a reason 指「合起来构成一个理由」）
a set of statements
phr.
2:40
一组陈述（statement 指有真假的陈述句）
premises
/ˈpremɪsɪz/
n.
3:09
前提（逻辑学术语，premise 的复数；注意与「房产」义区分）
conclusion
/kənˈkluːʒən/
n.
3:09
结论（论证中被前提支持的陈述）
support the conclusion
phr.
3:40
支持结论（指前提使结论更可能为真）
evaluate
/ɪˈvæljueɪt/
v.
3:40
评估、评价
consisted of
phr. v.
4:09
由……组成
as I indicated before
phr.
4:09
正如我之前指出的（indicate 此处＝point out）
unrelated to
phr.
4:40
与……无关的
doesn't do anything to make it more likely
phr.
4:40
丝毫没有让……更有可能（强调完全无贡献）
as it stands
phr.
5:08
就目前的样子而言、按现状来看
background premise
phr.
5:08
背景前提（隐含的、未明说的前提）
with the addition of
phr.
5:08
在加上……之后
considered in themselves
phr.
5:41
单就其本身而论
i.e.
abbr.
6:06
也就是说（拉丁 id est，用于解释说明，区别于 e.g. 举例）
point out
phr. v.
6:06
指出
deduce
/dɪˈduːs/
v.
6:34
推演、推断出（由已知前提得出必然结论）
given the premises
phr.
6:34
在给定前提的条件下
get over
phr. v.
7:06
克服（害羞、困难）；从……中恢复
suspend
/səˈspend/
v.
7:06
暂停、暂时中止（此处 suspend his policy 指暂时打破惯例）
unexpectedly
/ˌʌnɪkˈspektɪdli/
adv.
7:06
出人意料地
show up
phr. v.
7:06
露面、出现
merely
/ˈmɪrli/
adv.
7:35
仅仅、只不过
careful consideration
phr.
7:35
仔细审视、审慎考量
reveals
/rɪˈviːlz/
v.
7:35
揭示、显示出
reject
/rɪˈdʒekt/
v.
7:35
拒斥、否定（一个论证）
whereas
/werˈæz/
conj.
8:06
而、然而（用于对比两种情况）
object to
phr. v.
8:06
反对、反驳
missing the point
phr.
8:06
没抓住要点、误解了重点
taken for granted
phr.
8:06
被视为理所当然、默认接受
essential to
phr.
8:33
对……至关重要
summing up
phr. v.
8:33
总结、概括
introductory
/ˌɪntrəˈdʌktəri/
adj.
9:37
入门的、导论性的
理解自测 · 11 题 · 是真懂了，还是以为自己懂
1. 视频中批判性思维的定义是什么？
批判性思维是「确保你的信念有好理由」。讲者在开头（第 0 段）和总结（第 17 段）两次给出这一定义，并在第 3 段补充说，学习批判性思维要掌握的核心技能是区分相信某事的好理由与坏理由。它不是指「批评」或「怀疑一切」，而是对信念基础进行评估的能力。视频用朋友对「Monty 不会来派对」的三种解释来示范这一区分。
2. 朋友给出了哪三种理由？讲者分别如何评价？
第一种：「我受不了他，我想玩得开心」；第二种：「他非常害羞，很少去派对」；第三种：「他在北京，一个下午不可能赶到」。讲者认为第一种不是好理由，因为它与结论无关；第二种是好理由，因为它使结论很可能为真；第三种也是好理由，而且是最强的，因为若前提为真则结论必然为真。视频后半部分用红、橙、紫三色分别指代这三个论证。
3. 讲者说「好理由」中的「好」与什么无关、与什么有关？
与道德、伦理无关，与「真」相关。第 4 段明确说：基于好理由相信某事并不是道德上正确，基于坏理由相信也不是邪恶。这里的「好」指认识论意义上的好：一个好理由能使信念很可能为真，最好的理由能保证信念为真。这一澄清避免了把「你应该有好理由」误读为道德说教。
4. 论证由哪些部分构成？视频中用了什么例子？
论证是一组陈述，它们合起来构成支持另一陈述的理由。作为理由的陈述叫前提，被支持的陈述叫结论。视频（第 6 段）用朋友的第二个回答做例子：前提一「Monty 真的很害羞」，前提二「Monty 很少去派对」，结论「Monty 不会来派对」。讲者强调「合起来」——前提是作为整体提供支持的。
5. 为什么「我受不了他，我想玩得开心」不能支持「他不会来」这一结论？
因为这两个前提与结论「不相关」：它们为真与否，丝毫不改变 Monty 出席的概率。第 9 段指出，朋友的好恶和愿望「doesn't do anything to make it more likely」。好论证的定义是前提使结论更可能为真，而红色论证的前提对结论的概率没有任何贡献，所以它是坏论证。这种失败属于相关性缺失，而不是前提为假。
6. 在什么条件下红色论证可以变成好论证？这说明了什么？
如果补充一个背景前提：朋友正是决定邀请名单的人。这样「她讨厌 Monty 且想玩得开心」就成了「她没邀请他」的证据，从而支持「他不会来」。第 10 段用这个例子说明：论证好坏依赖于显性和隐含的前提，同一组陈述在不同背景下支持力不同。因此评估论证时要注意隐含前提，但讲者也强调（第 11 段）评价应针对「就目前给出的样子」。
7. 演绎论证和扩展性论证的区别是什么？如何检验一个论证属于哪一类？
演绎论证中，前提为真则结论必然为真（第 13 段）；扩展性论证中，前提为真使结论很可能，但不保证（第 14 段）。检验方法是想象反例：假设前提全部为真，结论是否仍可能为假？紫色论证（Monty 在北京且无法赶到）找不到反例，是演绎的；橙色论证（害羞、很少去派对）可以设想他破例出现，「不太可能但有可能」，所以是扩展性的。
8. 为什么讲者强调橙色和紫色论证「都是好论证」？这一强调针对什么误解？
针对「非演绎＝不可靠」的误解。第 12 至 15 段反复说明，两个论证结论相同、都为结论提供了好理由，只是支持强度不同。「好论证」的标准是前提使结论很可能为真，扩展性论证完全可以满足这一标准。讲者的推理链是：好理由＝提高概率（第 4 段）→ 好论证＝前提使结论很可能（第 7 段）→ 扩展性论证做到了这一点（第 14 段）→ 所以它是好论证，只是不演绎。
9. 为什么说用「结论仍可能为假」来反驳扩展性论证是「没抓住重点」？
因为扩展性论证从一开始就默认结论不由前提保证，这一点是「taken for granted」的。第 16 段说，指出前提不保证结论，不过是指出了它是扩展性论证这一事实，并没有构成批评。恰当的批评应当针对前提是否真的提高了结论的概率，例如提出 Monty 明确说过今晚会来的相反证据。相反，对于自称演绎的论证，找到反例就足以将其判定为坏论证（第 15 段）。
10. 如果有人反驳说：「按照讲者的标准，一个前提为假但结构上前提能保证结论的论证也算好论证，这不合理。」讲者会如何回应？
讲者可能会承认本课只讨论了「前提支持结论」这一维度，即前提与结论的逻辑关系，并未讨论前提本身是否为真。第 7 段和第 13 段的定义都是条件式的：「若前提为真，则结论很可能/必然为真」。这是刻意的分层：先学会判断支持关系，再在后续课程（第 17 段预告）引入有效性、可靠性等工具，把「前提为真」作为另一项独立要求。因此这一反驳指出了本课范围的局限，而非定义的错误。
11. 把「先判断论证类型再选评估工具」的原则用到日常场景，例如医生根据症状判断疾病，会有什么启示？
医生的诊断推理通常是扩展性的：症状使某种疾病很可能，但不排除其他可能。按讲者的原则，批评这种推理时不应说「你不能百分之百确定」，因为那是没抓住重点；应当问的是症状是否真的显著提高了该诊断的概率，是否有被忽略的相反证据或替代解释。反过来，若医生声称「这些指标必然意味着某病」，那就是在做演绎主张，一个反例即可推翻。区分类型可以让讨论聚焦在合适的标准上，避免双方各说各话。
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