Notes on Preface, Critical Thinking, and Syllogisms (Lies My Teacher Told Me)

Preface and purpose of the book

• Lowen evaluated a sample of high school US history textbooks to judge pedagogical value, accuracy, bias, and truthfulness. This motivates the book Lies My Teacher Told Me. The aim is to reveal how often textbooks mislead or misinform students.
• The preface argues that most texts performed poorly across these dimensions, illustrating the need for critical analysis rather than rote memorization.

Critical-thinking exercises vs. rote data

• Example: a critical-thinking exercise labeled as such asks students about Mayan calendars by presenting two counts: one from the Haab' calendar (365 days) and another from the Tzolk'in calendar (260 days).
  • Data presented: $260$ and $365$ days.
  • The critique: simply memorizing those numbers is not learning to think critically; it’s just data.
• What makes it critical thinking? Ask deeper questions:
  • Why is the first count so far off from the second?
  • How did they determine the second count so accurately?
• Insight from answering these questions:
  • Recognizes Mayan astronomy sophistication without European instruments or contact.
  • Encourages broader study of astronomy beyond Greek tradition (e.g., Ptolemy, Aristotle) and invites exploration of non-European scientific traditions.
  • Raises questions about calendar systems, astronomy, and the history of science.
• Broader lesson: why do we center European history in science/astronomy, and why not give Indigenous and non-European contributions more credit?
• Foreshadowing: Indigenous people of the Americas will be explored in Chapter 4; the book critiques biases like “Baffoeing labels” and the tendency to undercredit non-European groups.

The problem of “alternative facts” and the politics of truth

• The post-9/11/2010s-era phenomenon of “alternative facts” is discussed through a notable example:
  • Barack Obama’s inauguration claim: described as the largest audience in history, a statement that is objectively false when measured; the National Park Service released photographs that contradicted the claim.
  • The critique: labeling a false claim as an “alternative fact” conflates belief with truth and ignores evidence.
• The point about truth vs. opinion:
  • Ricky Gervais quote: "You're entitled to your own opinion, but you're not entitled to your own facts."
  • Distinguish between belief systems (morality, values) and empirical facts.
  • Some questions about truth treat truth as socially constructed, but the speaker argues that some propositions are objectively true or false and must be tested against evidence.
• Examples used to illustrate the distinction:
  • The American Civil War: a claim that it began in 1876 in Nevada due to a pay dispute between the Union Pacific Railroad and its Chinese workers is patently false; the war began in 1861 in South Carolina and was primarily about slavery, not just states’ rights.
  • Confederate Declarations of Secession: these documents repeatedly tie secession to the institution of slavery rather than states’ rights; this undermines claims that secession was primarily about states’ rights.
• Why do many people misattribute causes (e.g., “states’ rights” rather than slavery)?
  • Textbooks, especially in the South, influence beliefs; adoption boards and curricular choices shape nationwide trends, leading to similar misinformation in non-Southern states.
• Consequences of distorting the past:
  • Polling data showing widespread misperceptions about the Civil War.
  • The ethical and political stakes: miseducation can obscure racism, systemic oppression, and policy decisions that persist today.
  • The danger of “post-truth” thinking in public discourse and policy debates.
• The goal of critical thinking in this context: develop informed skepticism that evaluates claims against evidence rather than accepting opinions as facts.

Pseudoscience, race, and the enduring myths

• Genetic race theory: described as nineteenth- to twentieth-century pseudoscience that claims inherent racial differences in intelligence or ability.
  • Pseudoscience is science-like in presentation but lacks rigorous, reproducible evidence.
  • Example risk: claims about cognitive differences by race can be used to justify discrimination and inequity.
• The scientific counterpoint:
  • Modern genetics shows greater variation within racial groups than between them; race is more accurately described as a social construct than a strict biological category.
  • Even if some tests show differences in performance, those differences are strongly mediated by social factors (test bias, educational access, equity of opportunity) that can be addressed.
• The dangers of misusing science:
  • Once misused to justify slavery, segregation, colonialism, and systemic racism, such myths persist when reinforced by textbooks or media.
  • These myths persist in subtle forms, shaping prejudices and policies in the present day.
• Why the persistence matters:
  • Understanding the real basis of differences helps avoid discriminatory policies and supports a more accurate view of human variation.

Skepticism vs nihilism: which stance should we take?

• Informed skeptics vs nihilistic cynics:
  • Informed skeptic: evidence-based doubt that seeks truth through critical inquiry; not taking claims at face value.
  • Nihilistic cynic: distrust of all claims and sources; belief that truth cannot be known; often linked to extreme post-truth thinking.
• Preferred stance: be an informed skeptic who tests claims with evidence and reason.

Syllogisms: basic logic for evaluating arguments

• What is a syllogism?
  • A structured argument with three components: a major premise, a minor premise, and a conclusion.
  • Major Premise: $ext{All humans are mortal}$
  • Minor Premise: $ext{Socrates is a human}$
  • Conclusion: $ext{Socrates is mortal}$
• Why use syllogisms?
  • They provide a framework to test whether the conclusion follows from the premises.
• Types of syllogisms:
  • Catgeorical syllogism is the focus here (others exist but are not covered in this lecture).
• Valid vs. sound:
  • A syllogism is valid if the conclusion logically follows from the premises.
  • A syllogism is sound if it is valid and all its premises are true.
• Examples:
  • Sound syllogism (true premises lead to true conclusion):
  • Major Premise: $ext{All humans are mortal}$
  • Minor Premise: $ext{Socrates is a human}$
  • Conclusion: $ext{Socrates is mortal}$
  • Valid but not sound example (premises may be false):
  • Major Premise: $ext{All fish can talk}$
  • Minor Premise: $ext{Goldfish is a fish}$
  • Conclusion: $ext{Goldfish can talk}$
  • Here the form is valid, but the major premise is false, so the argument is not sound.
  • Invalid example (conclusion does not follow):
  • Major Premise: $ext{All cats are mammals}$
  • Minor Premise: $ext{All dogs are mammals}$
  • Conclusion: $ext{All dogs are cats}$
  • The structure is invalid; even if premises are true, the conclusion does not follow.

Hidden (unstated) premises: how to identify them

• Hidden premises are assumptions not explicitly stated but required for the argument to work.
• How to identify them (steps):
  1) Consider the conclusion. 2) Identify the stated premises and any evidence. 3) Ask what assumptions must be true for the argument to hold. 4) Evaluate whether that hidden premise is reasonable or flawed.
• Examples:
  • ‘We should leave now if we want good seats.’
  • Unstated premise: Early departure increases the chance of getting good seats.
  • ‘You should buy our moisturizer; it has aloe vera.’
  • Unstated premise: Aloe vera is good for your skin.
  • ‘We should trust her economic plan; she’s never run a business.’
  • Unstated premise: One must have run a business to craft a good economic plan (not necessarily true).
  • ‘We must ban single-use plastics.’
  • Unstated premise: Banning is the best solution to environmental harm (alternative approaches like regulation or taxes might exist).
  • ‘If someone loves you, they text you every day.’
  • Unstated premise: People who like someone communicate daily.
  • ‘Harvard graduates make good employees.’
  • Unstated premise: Harvard degree is a key predictor of being a good employee (could be false or not sufficient).
• The value of exposing hidden premises: helps avoid accepting weak or biased arguments; enables counter-arguments by challenging underlying assumptions.

Quick practice prompts (illustrative examples)

• Example 1: “We should skip dessert. It’s getting late.”
  • Unstated assumption: late dessert is bad for you (sleep disruption, circadian rhythm effects).
• Example 2: “She'll be a great leader. She's very charismatic.”
  • Unstated assumption: leadership requires charisma; other leadership qualities could suffice.
• Example 3: “My car is newer.”
  • Unstated assumption: newer implies better; other factors matter (maintenance, safety features).
• Example 4: “You'll love this movie; it's directed by Christopher Nolan.”
  • Unstated assumption: Nolan makes great films; a film by a famous director guarantees quality.
• Example 5: “We should increase security. Crime rates are rising.”
  • Unstated assumption: rising crime rates imply a need for more security; other measures could also address risk.
• These examples illustrate how to uncover the premises that must be true for the conclusion to hold, and how challenging them sharpens critical thinking.

Additional notes and connections

• The course plans to connect these concepts to broader historical inquiry:
  • Chapter 4 will cover Indigenous peoples of the Americas and related biases.
  • Chapter 5 will address how the Civil War is framed and the role of slavery in secession.
• The overarching aim is to arm students with tools to distinguish truth from opinion, to avoid passive acceptance of misleading data, and to challenge claims with evidence and logical analysis.
• It’s framed as preparation for a classroom activity (Kahoot) to reinforce critical-thinking skills and argumentation.

Key terms to remember

• Critical thinking: thoughtful, evidence-based analysis that questions assumptions and seeks well-supported conclusions.
• Alternative facts: claimed facts that conflict with objective evidence; a label for propagated misinformation.
• Post-truth world: a context in which emotional or personal belief can trump objective facts in public discourse.
• Pseudoscience: claims or practices that appear scientific but lack rigorous methodological support.
• Syllogism: a three-part argument (major premise, minor premise, conclusion) used to assess logical validity and soundness.
• Valid vs sound vs invalid: validity concerns logical form; soundness requires true premises.
• Hidden (unstated) premises: assumptions necessary for an argument that are not explicitly stated.

Note: The instructor mentioned that slides will be made available for further study, so students can review the specific examples and exercises in more depth.