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How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy
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How to Think: Introduction to Logic, Lecture 2 with David Gordon - Mises Academy

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For lecture videos, readings, and other class materials, you can sign up for this independent study course at academy.mises.org.

For lecture videos, readings, and other class materials, you can sign up for this independent study course at academy.mises.org.

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  • 1. Introduction to Logicwith David GordonLecture 2Mises AcademyFebruary 15, 2012
  • 2. When you heard the terrible news fromArizona, were you completely surprised? Orwere you, at some level, expecting somethinglike this atrocity to happen?. . . Last springPolitico.com reported on a surge in threatsagainst members of Congress, which werealready up by 300 percent. A number of thepeople making those threats had a history ofmental illness — but something about thecurrent state of America has been causing farmore disturbed people than before to act outtheir illness by threatening, or actuallyengaging in, political violence.And there’s not much question what haschanged. As Clarence Dupnik, the sheriffresponsible for dealing with the Arizonashootings, put it, it’s “the vitriolic rhetoric thatwe hear day in and day out from people in theradio business and some people in the TVbusiness.” The vast majority of those wholisten to that toxic rhetoric stop short of actualviolence, but some, inevitably, cross that line.
  • 3. When you heard the terrible news from Arizona, were youcompletely surprised? Or were you, at some level, expectingsomething like this atrocity to happen?. . . Last spring Politico.com reported on a surge in threats against members ofCongress, which were already up by 300 percent. A number ofthe people making those threats had a history of mental illness— but something about the current state of America has beencausing far more disturbed people than before to act outtheir illness by threatening, or actually engaging in, politicalviolence. And there’s not much question what has changed.As Clarence Dupnik, the sheriff responsible for dealing with theArizona shootings, put it, it’s “the vitriolic rhetoric that we hearday in and day out from people in the radio business and somepeople in the TV business.” The vast majority of those wholisten to that toxic rhetoric stop short of actual violence,but some, inevitably, cross that line.● Krugman says that an increase in “toxic rhetoric” willinevitably cause some people to cross the line intoviolence. But even if an increase in toxic rhetoricincreases the probability that some people will crossthe line, this doesn’t show: 1) that the increase inrhetoric makes it likely that someone will cross the lineor 2) that the increase in rhetoric causes someone tocross the line.
  • 4. ● Krugman has committed an ignoratio elenchi. He istrying to show that the increase in toxic rhetoriccauses an increase in violence. He instead showssomething else, i.e., that an increase in rhetoricincreases the chances that someone will be violent.● “Increase the chances” does not imply “makesprobable”● “Makes probable” does not imply “causes”
  • 5. “The first lesson is that property isoriginally communal (owned by thecommunity). Indeed, the very idea of apurely private property is a contradictionin terms, since the right to private propertymust be recognized by the community tohave any value. For example, the ownermust be able to call upon the police to beable to exclude others from his property,or his property cannot be said to beprivate at all.”Médaille, Toward a Truly Free Market
  • 6. ● “The first lesson is that property is originally communal(owned by the community).Indeed, the very idea of apurely private property is a contradiction in terms, sincethe right to private property must be recognized by thecommunity to have any value. For example, the ownermust be able to call upon the police to be able toexclude others from his property, or his property cannotbe said to be private at all.”--Médaille, Toward a Truly Free Market● The author claims that private property isoriginally communal, but he argues instead forsomething else---that the community mustrecognize private property if it is to have value.Again, an ignoratio elenchi.
  • 7. ● A Judgment affirms or denies an attribute ofa subject.● A Proposition is the verbal expression of aJudgment.● In Two Name Scholastic Logic, both subjectand predicate name the same thing.In “Socrates is mortal”, both “Socrates” and“mortal” are names of the same entity, i.e.,Socrates. “Mortal” is a way of referring toSocrates in this proposition.If it’s impossible to combine a predicate with asubject, the proposition isn’t allowed. “All dogsare reptiles” is not a legitimate proposition.
  • 8. ● In Two names Logic the verb is always “is”or “is not”.● This is one of the main areas whereScholastic Logic differs from mathematicallogic. Frege and Russell thought thatsubject-predicate logic can’t handlerelations.We thus have to change, “Hitler invades Russia”to “Hitler is invading Russia.” Otherwise, theproposition can’t be analyzed properly in this kindof Logic.The copula “is” indicates the existence or being,of the subject, but this doesn’t have to beexistence in reality. It can be existence in themind. e.g., “Hamlet was indecisive.”
  • 9. ● Quantity of propositions:■ A Universal affirmative■ I Particular affirmative■ E Universal negative■ O Particular negative● It’s very important to learn this table,because the Scholastic analysis of thesyllogism depends on this classification.● Some propositions are hard, but notimpossible to classify, e.g., SingularPropositions, Complex Propositions,and Compound propositions.
  • 10. ● Joyce says that in an analytic proposition,either: the predicate is contained in theintension of the subject, or the subject in theintension of the predicate.● A simpler way to understand this is that in ananalytic proposition, the predicate is part of theconcept of the subject or follows from theconcept of the subject.● Different from the logical positivist view thatanalytic propositions are conventional.● A synthetic proposition is one in which there isn’t a conceptual connection between the subjectand predicate.
  • 11. ● Two meanings of “possible”● Hypothetical propositions● Disjunctive propositions
  • 12. "If there is a dominant theme that runsthrough our discussion, it is this: Privateproperty is a legal convention, defined inpart by the tax system; therefore, the taxsystem cannot be evaluated by looking at itsimpact on private property, conceived assomething that has independent existenceand validity. Taxes must be evaluated aspart of the overall system of property rightsthat they help to create. . . The conventionalnature of property rights is both perfectlyobvious and remarkably easy to forget . . .We cannot start by taking as given . . . someinitial allocation of possessions— whatpeople own, what is theirs, prior togovernment interference"Liam Murphy and Thomas Nagel, The Mythof Ownership (Oxford, 2002), p.8
  • 13. "If there is a dominant theme that runs through ourdiscussion, it is this: Private property is a legalconvention, defined in part by the tax system; therefore,the tax system cannot be evaluated by looking at itsimpact on private property, conceived as something thathas independent existence and validity. Taxes must beevaluated as part of the overall system of property rightsthat they help to create. . . . The conventional nature ofproperty rights is both perfectly obvious and remarkablyeasy to forget . . . We cannot start by taking as given . . .some initial allocation of possessions— what peopleown, what is theirs, prior to government interference"● Murphy and Murphy are begging thequestion: they are claiming that propertyrights are conventional because propertyrights are conventional.● Note: “Beg the question” does not mean“raise the question.”
  • 14. Because in fact these high taxeconomies actually do well, it followsthat what happens in the real world isthat much of that tax money is spentconstructively, on programs thatinspire a sense of confidence,improve productivity, and promotegood health and education.--Jeff Madrick, The Case for Big Government,Princeton, 2009, p.17This is the famous post hoc, ergo propterhoc fallacy. If the government imposes hightaxes and the economy then did well, itdoesn’t follow that the high taxes contributedto the prosperity
  • 15. “Suppose there were a 100-percent probabilitythat unless prevented, a terrorist known to beloose in Manhattan would explode a nuclearbomb. No sane person would balk atabandonment of the conventional limitations onthe power to search and seize and the power toextract information from suspects and evenbystanders. Would he refuse to countenancean exception for a lesser threat to publicsafety? If the probability were 99 percent ratherthan 100 percent, could he sanely adhere tothat position? Eventually, a rule and exceptionapproach would dissolve into balancing, anddisagreement would shrink to differingassessments of the risks and harms“--Richard Posner, Law, Pragmatism, andDemocracy, (Harvard University Press, 2003),pp. 315-16.
  • 16. "Suppose there were a 100-percent probability thatunless prevented, a terrorist known to be loose inManhattan would explode a nuclear bomb. No saneperson would balk at abandonment of the conventionallimitations on the power to search and seize and thepower to extract information from suspects and evenbystanders. Would he refuse to countenance anexception for a lesser threat to public safety? If theprobability were 99 percent rather than 100 percent,could he sanely adhere to that position? Eventually, arule and exception approach would dissolve intobalancing, and disagreement would shrink to differingassessments of the risks and harms"● This is an example of the misuse of thesorites paradox.● If you start with a completely bald manand then add one hair, isn’t the personstill bald? But adding one hair can’tchange whether someone is bald.Therefore, someone with a full head ofhair is bald.
  • 17. Richard Posner responds the objection to judicialreview that it permits elitist judges to impose theirvalues on the rest of us in this way:"Liberalism is in tension with democracy.Democracy is a means not only of dispersingpolitical power and thus of protecting the privatesphere against invasion by the public sphere, butalso of enabling people to enforce their dislike ofother peoples self-regarding behavior“--Richard Posner, Overcoming Law, (Harvard, 1995), p.25.This is an ignoratio elenchi. Posner saysthere are problems with democracy. But evenif he is right, this doesn’t respond to the pointabout elitist judges.

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