4. The Horned Man 悖论 英文版 逻辑学教材
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Unit 5 conservatives and liberals保守派和革新派Conservatives and LiberalsRalph Waldo Emerson1. The two parties which divide the state, the party of Conservative and that of innovation, are very old, and have disputed the possession of the world ever since it was made. This quarrel is the subject of civil history. The conservative party established the reverend hierarchies and monarchies of the most ancient world. The battle of patrician and plebian, of parent state and colony, of old usage and accommodation to new facts, of the rich and, of the poor, reappears in all countries and times. The war rages not only in battlefields, in national councils, and ecclesiastical synods, but agitates every man’s bosom with opposing advantages every hour. On rolls the old world meantime, and now one, now the other gets the day, and still the fight renews itself as if for the first time, under new names and hot personalities.这个国家存在着两个政党,保守党和革新党。
逻辑学书单英文版摘要:1.逻辑学书单英文版的重要性2.逻辑学书单英文版的推荐书籍3.如何选择适合自己的逻辑学书单英文版书籍4.逻辑学书单英文版的学习方法和技巧5.逻辑学书单英文版对提高逻辑思维能力的帮助正文:逻辑学书单英文版对于学习逻辑学和提高逻辑思维能力具有重要意义。
逻辑学是研究推理规律的学科,它能帮助我们更加明确、有条理地思考问题。
通过阅读逻辑学书单英文版书籍,我们可以了解到不同的逻辑理论和方法,从而在实际应用中更好地运用逻辑学知识。
下面推荐几本逻辑学书单英文版的书籍,这些书籍都是在逻辑学领域具有较高影响力的作品:1.《逻辑学导论》(Introduction to Logic)作者:Irving M.Copi2.《形式逻辑》(Formal Logic)作者:Daniel V.Graham3.《逻辑思维》(How to Think Logically)作者:Gilbert R.Colman4.《逻辑思维训练100 例》(100 Logical Fallacies)作者:Robert J.Gerringer5.《启发式思维》(Gdel, Escher, Bach: An Eternal Golden Braid)作者:Douglas R.Hofstadter在选择逻辑学书单英文版书籍时,需要根据自己的兴趣和需求来选择。
对于初学者来说,可以先从入门级别的书籍开始,例如《逻辑学导论》。
对于已经有一定基础的读者,可以选择更具挑战性的书籍,如《形式逻辑》和《逻辑思维训练100 例》。
学习逻辑学书单英文版时,可以采用以下方法和技巧:1.制定学习计划:为了更好地学习逻辑学知识,可以制定一个合理的学习计划,每天安排一定的学习时间。
2.理论与实践相结合:在学习逻辑学理论知识的同时,要多做练习题,将所学知识应用到实际问题中。
3.多做总结和归纳:在学习过程中,要经常对所学知识进行总结和归纳,形成自己的知识体系。
4.参加讨论和交流:可以通过参加线上线下的讨论和交流活动,与他人分享学习心得,提高自己的逻辑思维能力。
Lesson 15Part One Warm-upBackground InformationI.Author Pre-class work:What do you know about Mark Twain? Can you name some books he wrote?Mark Twain (1835-1901) was born Samuel Langhorne Clemens in Florida, Missouri, but lived as a child in Hannibal, Missouri, on the Mississippi River. He took the pen name Mark Twain from the call of the pilots on the river steamers, which indicated that the water was twelve feet deep, a safe depth for a steamer. During his early years, he worked as a riverboat pilot, newspaper reporter, printer, and gold prospector. But then he turned to writing, and became one of the greatest of American writers.His works have been immensely popular, and have brought him an ample fortune, thus enabling him to devote his entire time to literature.Although his popular image is as the author of such humorous works as The Adventures of Tom Sawyer and The Adventures of Huckleberry Finn. Twain had the other side that may have resulted from the bitter experiences of his life: financial failure and the death of his wife and daughters. His last writings are savage, satiric, and pessimistic. The present text is taken from Letters from the Earth, one of his later works.●The Celebrated Jumping Frog of Calaveras Country《卡拉维拉斯县有名的跳娃》●The Innocents Abroad《傻瓜出国记》1869 A series of newspaper articles after hisEuropean trip later was published as this book. It explores the scrupulous individualism ina world of fantastic speculation and unstable values, and gives its name to theget-rich-quick years of the post Civil War era.《傻子出国记》为通讯集,是马克·吐温的旅欧报道。
逻辑学书单英文版以下是一些逻辑学的英文书单,涵盖了不同层次和主题的经典著作:1. "Introduction to Logic" by Irving M. Copi and Carl Cohen这本书是逻辑学入门的经典教材,涵盖了命题逻辑和谓词逻辑的基本概念和推理方法。
2. "Symbolic Logic and Mechanical Theorem Proving" by Chin-Liang Chang and Richard Char-Tung Lee该书深入介绍了逻辑学中的符号逻辑和机械定理证明方法,对于形式化推理和自动推理系统感兴趣的读者很有价值。
3. "Principia Mathematica" by Alfred North Whitehead and Bertrand Russell这是一部经典的数理逻辑著作,旨在通过逻辑系统化地推导数学定理,是逻辑学和哲学领域的重要里程碑。
4. "Gödel, Escher, Bach: An Eternal Golden Braid" by Douglas R. Hofstadter这本书以音乐家巴赫、艺术家艾舍尔和数学家哥德尔的作品为线索,探讨了逻辑、形式系统和人工智能等领域的交叉点,是一本富有启发性的哲学著作。
5. "Logic, Language, and Meaning: Introduction to Logic" by L.T.F. Gamut该书综合了逻辑学、语言学和语义学的内容,对于理解逻辑与语言的关系以及逻辑语义学的基本概念和方法非常有帮助。
6. "A Concise Introduction to Logic" by Patrick J. Hurley这本书是一本简明扼要的逻辑学导论,涵盖了基本的逻辑概念、推理形式和常见谬误,适合初学者阅读。
The sad young man悲哀的青年一代罗德.W.霍顿,赫伯特.W.爱德华兹1.二十年代社会生活的各个方面中,被人们评论得最多、渲染得最厉害的,莫过于青年一代的叛逆之行了。
只要有只言片语提到那个时期,就会勾起中年人怀旧的回忆和青年人好奇的提问。
中年人会回忆起第一次光顾非法酒店时的那种既高兴又不安的违法犯罪的刺激感,回忆起对清教徒式的道德规范的勇猛抨击,回忆起停在乡间小路上的小轿车里颠鸾倒凤的时髦爱情试验方式;青年人则会问起有关那时的一些纵情狂欢的爵士舞会,问起那成天背着酒葫芦、勾引得女人团团转的“美男子”,问起那些“时髦少女”和“闲荡牛仔”的奇装异服和古怪行为等等的情况。
“那时的青年果真这样狂放不羁吗?”今天的青年学生们不禁好奇地向他们的师长问起这样的问题。
“那时真的有过青年一代的问题吗?”对这类问题的回答必然只能是既“对”又“不对”——说“对”是因为人的成长过程中一贯就存在着所谓青年一代的问题;说“不对”是因为在当时的社会看来似乎是那么狂野,那么不负责任,那么不讲道德的行为,若是用今天的正确眼光去看的话,却远远没有今天的一些迷恋爵士乐的狂荡青年的堕落行为那么耸人听闻。
2.实际上,青年一代的叛逆行为是当时的时代条件的必然结果。
首先,值得记住的是,这种叛逆行为并不局限于美国,而是作为百年之中第一次惨烈的战争的后遗症影响到整个西方世界。
其次,在美国,有一些人已经很不情愿地认识到——如果不是明明白白地认识到,至少是下意识地认识到——无论在政治方面还是在传统方面,我们的国家已不再是与世隔绝的了;我们所取得的国际地位使我们永远也不能再退缩到狭隘道德规范的人造围墙之后,或是躲在相邻的两大洋的地理保护之中了。
3.在当时的美国,摒弃维多利亚式的温文尔雅无论如何都已经是无可避免的了。
美国工业的飞速发展及其所带来的庞大的、机器轰鸣的工厂的出现,社会化大生产的非人格性,以及争强好胜意识的空前高涨,使得在较为平静而少竞争的年代里所形成的温文尔雅的礼貌行为和谦谦忍让的道德风范完全没有半点栖身之地。
Lesson4 The Trial That Rockedthe World震撼世界的审判A buzz ran through the crowd as I took my place in the packedcourt on that swelter ing July day in 1925. The counsel for my defence was the famouscrimina l lawyerClarenc e Darrow.Leading counsel for the prosecu tion was William Jenning s Bryan, the silver-tongued orator, three times Democra tic nominee for Preside nt of the UnitedStates,and leaderof the fundame ntalis t movemen t that had brought about my trial.在一九二五年七月的那个酷热日子里,当我在挤得水泄不通的法庭里就位时,人群中响起一阵嘁嘁喳喳的议论声。
我的辩护人是著名刑事辩护律师克拉伦斯.达罗。
担任主控官的则是能说会道的演说家威廉.詹宁斯.布莱恩,他曾三次被民主党提名为美国总统候选人,而且还是导致我这次受审的基督教原教旨主义运动的领导人。
A few weeks beforeI had been an unknown school-teacher in Dayton, a littletown in the mountai ns of Tenness ee. Now I was involve d in a trial reporte d the world over. Seatedin court, ready to testify on my behalf,were a dozen disting uished profess ors and scienti sts, led by Profess or Kirtley Matherof Harvard Univers ity. More than 100 reporte rs were on hand, and even radio announc er s, who for the first time in history were to broadca st a jury trial. "Don't worry, son, we'll show them a few tricks," Darrowhad whisper ed throwin g a reassur ing arm round my shoulde r as we were waiting for the court to open.几个星期之前,我还只是田纳西州山区小镇戴顿的一名默默无闻的中学教员,而现在我却成了一次举世瞩目的庭审活动的当事人。
The Paradoxes of Eubulides of Miletus (4th century B.C.)3. The Heap(a.k.a. The Bald Man, a.k.a. The Sorites Paradox)I.The ParadoxConsider this obvious truth: addition of 1 kernel of wheat is too insignificant to turn what is not a heap of wheat into a heap of wheat and, similarly, subtraction of 1 kernel of wheat is too insignificant to turn what is a heap of wheat into what is not a heap of wheat.The obvious truth has the paradoxical consequences shown by the following Soritical argument:1. 1 grain of wheat is not a heap.2. If 1 grain of wheat is not a heap, then 2 grains of wheat are not a heap.[by the obvious truth] 3. If 2 grains of wheat are not a heap, then 3 grains of wheat are not a heap.[by the obvious truth] ...10,000. If 9,999 grains of wheat are not a heap, then 10,000 grains are not a heap.[by the obvious truth] Therefore, 10,000 grains of wheat are not a heap.The argument is valid. (In effect, it just uses 10,000 applications of the truth-preserving inference rule modus ponens.) And, its premises all seem to be true: (1) is clearly true; (2) is true by the obvious truth that addition of 1 little kernel can’t turn a non-heap into a heap; and (3)-(10,000) are true for the same reason. But, the conclusion is obviously false. So, the paradox here is, again, a seemingly sound argument with a false conclusion.II.The Heart of the MatterThe heart of the Heap paradox is captured in three assertions each of which seems true:a. small changes don’t make for a difference in the application of soritical predicates like‘…is a heap’ or ‘…is bald.’b. large changes do make for a difference in the application of such predicates,c. a large change is nothing more than a large number of small changes.But as the Soritical argument seems to show, the triad (a)-(c) is inconsistent, i.e., all of its members cannot be true together.III.FormalizationLet’s symbolize the Soritical argument:1. Fa12. Fa1⊃ Fa23. Fa2⊃ Fa3...n. Fa n-1⊃ Fa nn‘F’ is the predicate letter for the soritical predicate—in this case ‘…is not a heap’—and ‘a1’, ‘a2’, etc. are individual constants denoting the objects to which the pr edicate applies, e.g., 1 kernel of wheat, a collection of 2 kernels of wheat, etc.The general conditions for a Sorites argument are:i. the series a1-a n is ordered consecutively (e.g. by increasing number of kernels),ii. ‘F’ satisfies the foll owing conditions:a. it is true of a1b. it is false of a nc. each adjacent pair in the series, a j and a j+1, are similar enough so as not to differ inrespect of ‘F.’[Thus, we can construct a more emotionally compelling Sorites ar gument with ‘F’ interpreted as ‘is not a person’ and the series a1-a n denoting the stages of embryonic development fromzygote to infant.]III.VaguenessThe source of the Sorites paradox is the semantic phenomenon of vagueness: a word’s or concept’s having a gray area of application, i.e., borderline or indeterminate cases, circumstances in which the word or concept neither clearly applies nor clearly fails to apply.If every word or concept were as precise as, say, rational number, which has no borderline cases, then there would be no Sorites paradox. That is, if there were a sharp boundary for ‘…is not a heap’—a number k such that k grains clearly were not a heap but k+1 grains clearly were a heap—then one of the premises in the Sorites argument would be false. Specifically, the k+1st premise—Fa k⊃ Fa k+1—would be false, for ‘Fa k’ (‘k grains of wheat is not a heap’) would be true but ‘Fa k+1’ (‘k+1 grains of wheat is not a heap’) would be false.1 So, we’d no longer have a sound argument with a fa lse conclusion.1 Remember, a conditional with a true antecedent and a false consequent is false.But, ‘…is not a heap,’ ‘…is bald,’ etc. certainly don’t seem to have such sharp boundaries. So, we seem stuck with the paradox.IV . ReactionsA . Natural Language isn’t LogicalOne proposal is to deny that formal logic characterizes natural language —at least until its vague predicates are replaced with precise ones —for the symbolic languages of formal logic are deliberately precise while natural languages are lousy with vagueness.2I don’t care for this approach. For, arguments w hose premises and conclusions are expressed in natural language can be valid or not. Indeed, natural language arguments constructed with vague predicates can be valid or not. And validity is certainly within the scope of formal logic.B . Ignorance of Sharp MeaningsAnother proposal is to claim that, despite appearances, one of the premises inSoritical arguments is really false. It follows that there really is a sharp boundary for every soritical predicate like ‘…is a heap’—some specific number which sharply distinguishes heaps from non-heaps.To defend this idea, let me recast the form of the Soritical argument from a series of conditional premises to a single universal premise: 2 This was Frege’s attitude as well as Russell’s.1. Fa 12. (∀n )(Fa n ⊃ Fa n + 1) 10,0001. The man with no hair on his head is bald.2. For any number n , if the man with n hairs is bald, then the man with n+1 hairs is bald. Therefore, (3) the man with 10,000 hairs on his head is bald. The argument is valid. Since (1) is undeniably true and (3) is undeniably false, avoiding the paradox requires that premise (2) be false. Therefore:~(∀n )(Fa n ⊃ Fa n + 1).Hence:(∃n )~(Fa n ⊃ Fa n + 1).[by QN] Thus:(∃n )(Fa n & ~Fa n + 1). [by material implication and De Morgan’s law]That is, there does exist a particular number, call it k , such that the man with k hairs on his head is bald but the man with k +1 hairs is not bald. It’s just that we don’t (or can’t) knowwhat k is. In other words, there really are no vague words or concepts, and what seems like vagueness is not a semantic phenomenon but rather the result of our ignorance about the precise meanings of our own words and concepts.I don’t like this reply either. Language is our creation, and there isn’t more to it than we put in it. So, it is very implausible that the meanings of our terms should be so far beyond our knowledge.C. Fuzzy Set Theory and Fuzzy LogicThere is an intuitive connection between an object’s membership in a set and the truth of a sentence that predicates a property of the object, viz. if a belongs to the set of F-things—a∈ {x∣x is F}—then the sentence ‘F a’ is true. Intuitively, then, it seems that any object is either in or out of a given set.According to fuzzy set theory, on the other hand, there are an (uncountably) infinite number of degrees of set membership, as many degrees as there are real numbers in [0, 1]. So, a can be completely non-F, …, a little F, …, a little more F, …, pretty F, …, quite F, …, very F, …, or fully F. An d, there are correspondingly many degrees of truth: if a∈ to degree n {x∣x is F}, then ‘F a’ is true to degree n. For example, as a man loses more and more hair, he becomes more and more bald and the assertion ‘S is bald’ becomes more and more true.In theory, the concept of degrees of truth implies degrees of validity, and, with further development, the fuzzy theorist hopes to show that the conclusion of a Soritical argument does not follow from its premises with a sufficient degree of validity to be paradoxical.I won’t pursue the development of this solution because I already find it enormously implausible that our concept of truth should be so unbelievably refined as to include a non-denumerably infinite number of distinct truth-values.D. Truth-Value Gaps.In the classical logic that we’ve studied, there are two, and only two, truth-values: the true and the false. Fuzzy logic is an example of non-classical (or deviant) logic of the sort called many-valued.A logic of truth-value gaps is a different sort of non-classical logical theory. For example, if ‘71 kernels is not a heap’ is neither clearly true nor clearly false, then it has no truth-value—the sentence is a truth-value gap. This promises to resolve the paradox, for if there are premises in a Soritical argument that get no truth-value, then the argument is no longer sound.However, it is not obvious that truth-value gaps will resolve the paradox. Imagine that we adopt a gappy logical theory where some sentences with vague predicates—likepremise (1) of the Soritical heap-argument—are true, some—like that argument’s conclusion—are false, and some—the borderline cases—are truth-value gaps.This proposal leaves us with a new and very similar problem: precisely which sentences get no truth-value? That is, precisely which cases are the borderline cases? The situation here is not that fewer than, say, 500 grains clearly is not a heap, more than 1000 grains clearly is a heap, and between 501 and 999 grains clearly is borderline. On the contrary, it is very unclear whether 900 grains is a clear heap or a clear borderline case.In other words, the concept borderline case is itself vague—it also has borderline cases! So, even if we treat the problem of vagueness by acknowledging three truth statuses—true, false, and neither true nor false—we still face the vagueness problem of determining which sentences have which truth statuses.。
The Paradoxes of Eubulides of Megara (4th century B.C.)4.The Horned ManI.The ParadoxAssuming you don’t suffer from calvarial homoplastic osteomata, consider:You still have what you have not lost.You have not lost horns.Therefore, you still have horns.Again, the paradox is a seemingly sound argument with a false conclusion.The Horned Man introduces the phenomenon of presupposition, a subject that most naturally arises in considering definite descriptions, i.e., phrases of the form ‘the Φ’ (like ‘the puppy in the window’) that purport to refer to a specific individual, viz., the unique (relevant) thing that is Φ.II.Strawson vs. Russell on the Analysis of Definite DescriptionsConsider the sentence:1. Joe is tall.As we learned when studying predicate logic, (1) is a singular proposition, i.e., a proposition about one specific object, for the sentence says that the individual denoted by the designating expression ‘Joe’ possesses the property expressed by the predicate expression ‘…is tall.’ Thus, we formalize (1) as:1'. Tj j: JoeT x: x is tallNow, consider the following sentence, which contains a definite description ratherthan a name:2. The puppy in the window is purebred.P.F. Strawson argued that (2) is also a singular proposition, and, so, he took definite descriptions to be designating expressions. On his view, the logical form of (2) is:2'. P the Φthe Φ: the unique puppy that is in the (salient) windowP x: x is purebredCall the definite description ‘the Φ’ a quasi-name.Bertrand Russell argued against Strawson that, contrary to its appearance, a definite description is a quantifier construction rather than a designating expression. For example, Russell argued that the sentence:3. The king of France is bald.asserts that there exists one and only one object that has the property of being the king of France, and the unique individual with that property also has the property of baldness. That is, (3) is an existentially quantified general proposition, not a singular proposition. Thus, (3) has the logical form:3'. (∃x)(((F x∧ (∀y)(F y⊃y = x)) ∧ B x)F x: x is a king of FranceB x: x is baldThat is: There exists an x such that x is a king of France, and if any y is a king of France, t hen it is identical to x; and x is bald.On Strawson’s theory, (3) is formalized as:3''. B the F the F: the king of Francewhere ‘the F’ is a designating expression, a quasi-name, denoting the specific individual that is the king of France.Summing up their disagreement, Russell claims that (3) asserts that there is one and only one object that is king of France, and it asserts that that object, whichever it is, is bald. Strawson claims that (3) presupposes, but does not assert, that there is one and only one object that is king of France, and it asserts that that specific individual is bald.III.Strawsonian PresuppositionConsider some more of Strawson’s examples:4. Wellington’s victory at Waterloo was his greatest triumph.5. All John’s children are asleep.According to Strawson, (4) asserts a singular proposition: a specific event—the one picked out by the quasi-name ‘Wellington’s victory at Waterloo’—has the property of b eing Wellington’s greatest triumph. But in order to assert that that event possesses that property, (4) must presuppose (though not assert) that that event occurred, i.e., that Wellington was victorious at Waterloo.Sentence (5) asserts the general pro position that each member of the class of John’s children is asleep. And in order to assert this about each member of the class, (5) must presuppose (though not assert) that the class has members, i.e., that John has children.OK, so precisely what is Strawsonian presupposition?A. Sentences vs. StatementsIn order to provide a precise account, we must consider the distinction that Strawson draws between a sentence and a statement. A sentence is a linguistic type; it is meaningful, but it doesn’t ac tually assert anything. It is speakers, not sentences, that make assertions, which they do by making statements. A statement is a token of a sentence type; it is a speaker’s particular use of a sentence at a particular time and in specific circumstances in order to make an assertion. For example, sentence (3) above means that the king of France is bald, but it doesn’t assert anything. However, if it is 1650, then Pierre can assert that Louis XIV is bald by using (3) to make the statement that Louis XIV is bald.And if it is 1789, then Françoise can make the different assertion that Louis XVI is bald by using the same sentence to make the different statement that Louis XVI is bald.So, a speaker’s use of a sentence produces a statement.Now, a use of an expression type is an utterance tokening of it with certain intentions. For example, in the course of uttering sentence (3), Pierre uttered ‘the king of France’ with the intention of referring to Louis XIV, and the fact that Françoise’s use of t he same sentence was different from Pierre’s use consists in the fact that she uttered ‘the king of France’ with the different intention of referring to Louis XVI.Since it is only when speakers use sentences to make statements that anything at all gets asserted, only statements have truth-values. And, a speaker’s use of a sentence type determines the truth conditions for his statement. Thus, Pierre’s statement is true if and only if Louis XIV is bald, and it is false if and only if Louis XIV is not bald, and Françoise’s statement is true if and only if Louis XVI is bald, and it is false if and only if Louis XVI is not bald.B. PresuppositionCall Françoise’s statement that the king of France is bald ‘S.’ Now, if S is true if and only if Louis XVI is bald and false if and only if Louis XVI is not bald, then it follows that her statement can be either true or false only if the king of France (at the time of her utterance) is Louis XVI.Now, let ‘S'’ be the (possible) statement (in 1789) that t he king of France is Louis XVI.The truth of ‘S'’ is a necessary condition for ‘S’ to be either true or false, i.e., to have a truth-value at all. In this sense, ‘S’ presupposes‘S'.’C. Presupposition FailureSince ‘S'’ must be true for ‘S’ to even have a truth-value, it follows that if ‘S'’ is false, then ‘S’ is neither true nor false. S is a truth-value gap.This conclusion about truth-value gaps makes sense in the light of Strawson’s view about statements. Consider Bertrand’s use in 1905 of sentence (3) to state that the king of France is bald. France had no king in 1905 at the time of Bertrand’s utterance. So, his intention to refer to a specific individual failed, and his use of the quasi-name ‘the king of France’ was vacuous.Sinc e he didn’t succeed in referring to anything at all, it follows that he just wasn’t talking about anything. And, if he just wasn’t talking about anything, then it follows that he failed to make any genuine assertion at all. So, Bertrand failed to make a statement.Since it is only statements that have truth-values, it stands to reason that Bertrand’s utterance of (3) had no truth-value.Similarly, a use of sentence (4) to make the statement that Wellington’s victory at Waterloo was his greatest triumph presupposes the truth of the (possible) statement that Wellington was victorious at Waterloo. If Wellington was not victorious at Waterloo, then a speaker’s utterance of ‘Wellington’s victory at Waterloo’ would fail to refer, and, consequently, her use of (4) would fail to make a statement. Consequent ly, the speaker’s utterance would fail to be either true or false.1IV.Return to the Horned ManPresupposition resolves our trouble with the Horned Man paradox. For, the statement of the argument’s first premise:i. You still have what you have not lostpresupposes the statement:i´. You do possess the relevant thing.Now, (i´) is false in the case of your horns. Since its presupposition fails, the statement of (i) is a truth-value gap. Since the statement of (i) has no truth-value, it follows that that statement is not true. Therefore, the Horned Man argument is not sound. And, the paradox is resolved.1A problem for Strawson: My statement ‘The king of France shot my cat last night’ i s clearly false; however, on Strawson’s view it gets no truth-value.。