这应该是全书中最要命的一章了。
Seven of the most important and widely used of these tactics are discussed in this chapter: definitions, distinctions, analysis (in a narrow sense), dilemmas, counterexamples, reductio ad absurdum arguments, and dialectical reasoning.
1 Definitions
不是每个词都可以被定义，否则会陷入无穷倒退；故而定义的条件是：
The short answer is that a word must be defined if (1) it is used with a technical meaning and it cannot be assumed that the audience will know that technical meaning; or if (2) it is an ordinary word used in a nonordinary sense.
For us it is enough to say that the general purpose of definition is to make the meaning of a word or phrase clear. Depending upon the author’s needs, this can be done either by describing the actual use of a word or phrase (descriptive definition), making the actual use of a word or phrase more precise (precising definition), or by inventing a new word or giving an existing word a technical definition (stipulative definition).引自 Chapter 5 Tactics for Analytic Writing
受形式逻辑的影响，20世纪以来哲学家定义的方式发生了变化，例如：
knowledge is justified true belief →
x knows that p if and only if
(1) it is true that p;
(2) x believes that p; and
(3) x’s belief that p is justified.
It often turns out that philosophers need to define pairs of terms that they want to be contradictories.
这种方式也即从与所要定义者相矛盾处出发，为了说明某物是是什么，则先要说明某物不是什么。
2 Distinctions
Distinctions should be made only when they are necessary and justified.
A good distinction, called a proper distinction, has two characteristics: its terms are exhaustive, and they are mutually exclusive. A pair of terms is exhaustive when at least one of them applies to each object of the group that is supposed to be distinguished. A pair of terms are (is) mutually exclusive when only one of the terms applies to each object.引自 Chapter 5 Tactics for Analytic Writing
恰当的区分在于一组术语应当是详细且互斥的，例如Red & non-red
区分有两种途径，一种是通过举例（by example），一种是通过描述特征（by characterization）。但前者的缺陷在于可能无法让读者明白区分的原则（the principle）何在，后者在理论上更具优势，但务必要列出差异（difference），否则区分也是无效的。
3 Analysis
Analyses are explicitly about giving the necessary and sufficient conditions for concepts.
分析由两部分构成，被分析项（analysandum） 和分析项（analysans）。
An analysis tries to specify in its analysans necessary and sufficient conditions for the concept expressed in the analysandum.引自 Chapter 5 Tactics for Analytic Writing
所需要注意的是，为避免分析无力，必要条件是分析项所必须的。
而一个不过关的分析常常出现的问题是：循环定义；分析过度或不足（ being circular, being too strong, or being too weak）。
在循环定义黜，作者提及了还原论：运用奥康剃刀，如无必要，勿增实体，以求分析项简洁。显然还原论是不允许出现循环定义的，但它仍然无法避免循环定义的产生。分析过度或不足则指的是分析项过于严格或者简略。
分析项中的术语应当更为基本，作者在这里提出一个细节，即某些看似已经足够基本的对应词（correlative terms）往往可以进一步分析以避免循环定义。例如：
A husband is a person that has a wife.
A wife is a person that has a husband.
→
A husband is a male spouse.
A wife is a female spouse.
4 Dilemmas
这也是分析手段中的一种，它甚至可以成为一篇文章的中心。困境亦分为两种：material dilemmas与formal dilemmas，后者与论证的前提与结论都无涉，而这一章要讨论的主要是前者。
dilemma又有constructive and destructive dilemmas——他们在形式上没有问题的，那么解决的方式就是证明其中某一个前提是错误的；这里三种方式：
(1) Showing that the disjunctive premise is false is called “going between the horns of the dilemma”. To show that the disjunctive premise is false is to show that both disjuncts are false and that there is some third possibility that is true.
(2) Showing that the conjunctive premise is false is called “grabbing the dilemma by the horns.” It consists of showing that at least one of the conjuncts is false.
(3) Producing a counterdilemma. This typically consists of producing a dilemma that has the same disjunctive premise. The conjunctive premise keeps the same antecedents; but the consequents typically are contraries to the disjuncts of the conclusion of the original dilemma.引自 Chapter 5 Tactics for Analytic Writing
As its name suggests, a scenario is a detailed description of a situation that perspicuously establishes the intended point.引自 Chapter 5 Tactics for Analytic Writing
值得注意的问题是，某些含有讽刺意味的情境设置不等于那些会歪曲命题的嘲讽漫画，后者是无法反驳或证明某个观点的；对某一场景的描述，不应当有偏见或者用尚处争议的情况；对于情境的描述应当充分。
6 Counterexamples
The method of counterexample is a powerful tool, frequently used to refute a philosophical view.
反例分为 propositional counterexample 和 argumental counterexample。前者通常所针对的是全称命题（universal proposition），后者则往往不仅仅针对单个命题；也有两者相结合的事例。虽然反例十分有效，甚至可以直接驳倒某个论点，但前提是读者能够辨别出得出来。
7 Reductio ad Absurdum
A method of argument that begins with the opposite of the proposition that is to be proved. From that opposite, one shows that absurd consequences follow. Since the opposite is absurd, the proposition to be proved must be true.引自 Chapter 5 Tactics for Analytic Writing
In this sense, dialectical reasoning is characterized by the following:
(a) It is reasoning that proceeds by considering a series of topically related propositions.
(b) Each succeeding proposition usually comes out of or is inspired by prior propositions.
(c) Each succeeding proposition is supposed to be closer to the truth than any earlier one.引自 Chapter 5 Tactics for Analytic Writing
第一种是黑格尔意义上的，也就是我们所熟知的正反合；第二种则由negation、expansion和hedging构成，第一步是否定，第二步是扩展论述，第三步则是弱化（weakening），也就是讲结论调整，变得更为恰当和严谨；第三种则是循循善诱，一步步带领读者深入证明，这种模式往往会伴有对话式的写作体裁，不过作者提醒这种写作体裁虽好，却不适合每个人。原因在于这可能会导致读者把可爱（cuteness）或幽默（humor）当做严密论证的替代，其次是会导致离题（digression）。
不过这种方式容易组织文章，如下：
On the one hand, X
On the other hand, not-X, because of P
Then again, X because of Q
On the other hand, not-X because of R
表示其中内容是对原文的摘抄