Critical Thinking: Deductive Forms, Milgram & Zimbardo, Cognitive Development, and Skepticism

Form: two premises then the conclusion
Structure (logic): $(A \rightarrow B), A \vdash B$
Explanation: From a conditional $A \rightarrow B$ and the antecedent $A$, infer the consequent $B$
Key terms: antecedent = $A$, consequent = $B$

Form: from a conditional and the negation of the consequent, infer the negation of the antecedent
Structure: $(A \rightarrow B), \neg B \vdash \neg A$
Explanation: If $A \rightarrow B$ and $\neg B$ , then $\neg A$

Form: from $A \rightarrow B$ and $B \rightarrow C$ , infer $A \rightarrow C$
Structure: $(A \rightarrow B), (B \rightarrow C) \vdash (A \rightarrow C)$
Notes: also considered a hypothetical syllogism; connects a sequence of conditionals

Purpose: test obedience to authority and willingness to harm others under instruction
Location/lead: Yale University; Stanley Milgram
Design: participants as teachers; learners as confederates; shocks supposedly for memory tasks; draws manipulated to create belief of 50/50 roles
Procedure: shocks increased with wrong answers up to 450 volts; shocks not real
Result: $65\%$ delivered up to 450 volts; $35\%$ refused before max
Lesson: ordinary people may follow authority to commit harm; critical thinking helps resist
Ethical note: not permissible by today’s standards; time capsules for understanding authority dynamics

Purpose: examine power dynamics in a simulated prison
Location/lead: Stanford University; Philip Zimbardo
Design: volunteers randomly assigned as guards or prisoners; mock prison in basement; uniforms to depersonalize
Outcome: escalation of abusive, dehumanizing behavior; some prisoners experienced severe distress
Duration: intended two weeks but halted after 6 days
Lesson: authority and role conformity can drive cruel behavior; need for oversight and ethical safeguards
takeaway: good critical thinking helps resist abusive roles and authority when warranted

Concept: lifelong process of acquiring intelligent/reflective thinking
Three stages/phases:
- Dualism: truth is black-and-white; authority figures know the truth; passively defer to them
- Relativism: truth is relative; all opinions have equal standing; risk of paralysis from excessive skepticism
- Commitment: combine reason with evidence to form one's own well-supported beliefs; open to revision with new evidence
Key idea: progression moves from reliance on authorities to independent, evidence-based judgment

Analytical skills: provide logical support for beliefs; avoid unfounded opinions
Effective communication: clear speaking/writing; strong listening; adapt to audience and style
Research/inquiry skills: gather/evaluate evidence; distinguish reliable sources; synthesize information
Flexibility: willing to change minds/plans when warranted; remain open to alternatives
Open-minded skepticism: balance skepticism with openness; require good evidence; avoid prejudgment

Open-minded skepticism: evaluate evidence before belief; avoid credulity; remain willing to revise
Method of doubt (Descartes): seek certainty by doubting anything that can be doubted
Core idea: doubt as a systematic tool to reach secure beliefs; provisional conviction only when indubitable
Famous outcome: cogito — $\text{Cogito ergo sum}$ (I think, therefore I am)
Context: 17th century age of reason; Descartes sought a solid foundation for knowledge
Practical takeaway: maintain healthy doubt while demanding evidence before belief

Even if external reality were doubtful, thinking is occurring, so the thinker’s existence is confirmed
Therefore, at minimum, consciousness exists as a thinking thing