先来做个测试玩一玩：什么是批判性思维？
你能用自己的语言解释给别人吗？
也许你会说，我知道啊，可是我说不出来啊？如果说不出来，别人怎么知道你到底是知道还是不知道。
如果不知道，请回到第二章，看看作者对批判性思维的定义：
Critical thinking, therefore, may be defined as the process by which we test claims and arguments and determine which have merit and which do not. In other words, critical thinking is a search for answers, aquest.
如果看到英文解释，你仍然不能用中文表达出来，说明你还是没有完全理解，你游走在知道和不知都之间。
那么“知道”意味着什么？
我们知道的东西就是知识，”知道“意味你拥有某方面的知识，获取知识的过程就是认知的过程。
作为批判性思维者，你知道的越多，你对自己的知识就越有把握，就越有可能对他人的观点提出质疑，就越可能发现事实。
原文中有一句话：The more of the eight items you “knew,” and the surer you were of your “knowledge,” the more troubling you are likely to find these facts. 文中“knew”和”knowledge”是加了引号的，所以是主观认为的知识和知识，并不是事实。意思是：这8个问题你认为知道的越多，你会对自己的知识越肯定，那么你发现事实会越有难度。要特别注意这种伪知识。
在这个章节我们可以学习到认知的必要条件、如何认知，为什么认知是困难的，认知中存在的哪些障碍。
我们不但要知道自己知道什么，还要知道自己不知道什么。
每日五词
1.have/keep somebody on a short/tight leash
to have a lot of control over someone's behaviour and allow them very little freedom to do what they want He doesn't go out with the lads so much these days. Michelle keeps him on a tight leash.
2.debunk
指出…的错误;揭穿…的吹嘘或虚假；If youdebunka widely held belief, you show that it is false. If youdebunksomething that is widely admired, you show that it is not as good as people think it is.[V n]
Historian Michael Beschloss debunks a few myths.
历史学家迈克尔·贝施洛斯破除了几个不实传言。
3.Rumor game
It begins when one person writes down a message but doesn’t show it to anyone. Then the person whispers it, word for word, to another person. That person, in turn, whispers it to still another, and so on, through all the people playing the game. The last person writes down the message word for word as he or she hears it. Then the two written statements are compared.
4.subsist
maintain or support oneself, especially at a minimal level
（尤指最低限度地）生存, 糊口, 勉强维持生活：
hesubsisted onwelfare and casual labour.
他靠救济金和当临时工维持生活。
5. stifle
[VERB 动词] 扼杀;压制;抑止；If someonestiflessomething you consider to be a good thing, they prevent it from continuing.[V n] [disapproval]
Regulations on children stifled creativity...
给孩子们定的各种规矩扼杀了他们的创造力。
Summary
Chapter 4 begins with a story about spelling of a word with which the author introduce the conception of knowing.
Requirements of knowing
- Knowing involves having the right answer and realization that you have it.
- have the ability to express what is known and how we came to know it.
How We Come to Know
- Actively
We actively achieve knowledge by direct experience, by testing and proving an idea, or by reasoning.
- Passively
We achieve knowledge passively by being told something by some- one else.
Learning in classroom, from Tv, newspaper or magazines is passive.We should be aware of the defects of passive learning.
Why Knowing Is Difficult
- There are long unanswered questions continue to resist solution, questions.
- Everyday situations arise for which there are no precedents.
- Previous knowledge is often forgotten or unwisely rejected.
Obstacles to Knowledge
- Assuming
Assumingis taking something for granted.
It stops curiosity.
- Guessing
Guessingis offering a judgment on a hunch or taking a chance on an answer without any confidence that it is correct.
It denies importance of evidence.
感悟：
在这章里又出现了Mortimer Adler的名字，《如何阅读一本书》的作者，好亲切。
To admit you don’t know something shows good sense, restraint, and intellectual honesty. These are not weaknesses but strengths. The admission of ignorance is the essential first step toward knowledge.
承认自己不知道并不是缺点而是有点。知道自己不知道是通往知识的关键一步。
从知道和不知道的角度说一说创新——这个时代最关注的东西。
我们有知道的东西，就是知识；我们知道有不知道的东西，通过已有的知识解决未知，把不知道变成知道；重要的是，要知道我们还有不知道不知道的东西，把不知道不知道变成知道不知道，再变为知道，这个过程就是创新。
为什创新是一个难题，以为大部分人做到知道都有难度。
