PHI 1103: Critical Thinking - Second Exam Study Guide

Comprehensive vocabulary flashcards covering logic, formal arguments, truth tables, cognitive biases, heuristics, causation, and epistemology for the PHI 1103 Critical Thinking exam.

Argument

A set of statements in which one or more statements (premises) are offered as reasons or evidence to support another statement (the conclusion).

Premises

Statements offered as reasons or evidence to support another statement (the conclusion).

Conclusion

The claim in an argument that the premises are intended to establish.

Proposition

The meaning or claim expressed by a declarative sentence that has an objective truth value (true or false).

Dual Systems Theory

The psychological theory stating that human thinking operates through two distinct cognitive modes: System 1 and System 2.

System 1

A mode of thinking that is fast, automatic, intuitive, and low-effort, frequently relying on emotions, habits, and mental shortcuts.

System 2

A mode of thinking that is slower, deliberate, analytical, and effortful, supporting careful reasoning and problem-solving.

Deductive Argument

An argument that attempts to guarantee that the conclusion follows necessarily from the premises, evaluated as valid or invalid.

Inductive Argument

An argument that attempts to make the conclusion probable based on the premises, evaluated as strong or weak.

Valid Argument

A deductive argument structured such that it is impossible for all premises to be true and the conclusion false at the same time.

Sound Argument

A deductive argument that is logically valid and contains all true premises.

Logical Possibility

The status of a state of affairs or claim that involves no logical contradiction.

Physical Possibility

What is possible under the laws of nature.

Psychological Possibility

What a person is mentally capable of thinking, imagining, or experiencing.

Physiological Possibility

What is possible given the capabilities and limitations of the human body.

Belief Bias

The cognitive error of judging an argument's quality based on whether one agrees with its conclusion rather than its logical validity.

Motivated Reasoning

Processing information in a biased manner in order to reach a conclusion one already desires to believe.

Counterexample

An example that demonstrates a claim or argument is false, such as a possible scenario where all premises are true and the conclusion is false.

Truth Table

A tabular diagram listing every possible truth-value combination of component propositions and the resulting truth value of the complex proposition.

Negation ($\neg P$)

A truth-functional operator that reverses the truth value of a proposition.

Conjunction ($P \wedge Q$)

A truth-functional connective that yields true only when both conjuncts are true.

Disjunction ($P \vee Q$)

An inclusive truth-functional connective that yields true when at least one disjunct is true.

Material Conditional ($P \rightarrow Q$)

A truth-functional connective that is false only when the antecedent $P$ is true and the consequent $Q$ is false.

Material Biconditional ($P \leftrightarrow Q$)

A truth-functional connective that is true when both component propositions share the same truth value.

Modus Ponens

A valid argument form: If $P$ then $Q$; $P$; therefore $Q$.

Modus Tollens

A valid argument form: If $P$ then $Q$; not $Q$; therefore not $P$.

Affirming the Consequent

An invalid deductive fallacy with the form: If $P$ then $Q$; $Q$; therefore $P$.

Denying the Antecedent

An invalid deductive fallacy with the form: If $P$ then $Q$; not $P$; therefore not $Q$.

Sufficient Condition

A condition that is completely enough to guarantee that another condition occurs.

Necessary Condition

A condition that must be present in order for another condition to occur.

Principle of Charity

The interpretative practice of evaluating another person's argument in its strongest, most reasonable formulation.

Enthymeme

An argument that contains an unstated or missing premise or conclusion.

Explanation

A statement or discourse that describes why or how something happened, clarifying something already accepted as true rather than proving it.

Statistical Syllogism

An inductive argument that uses a known statistic about a group to draw a probable conclusion regarding an individual member of that group.

Rule of Total Evidence

The inductive principle requiring one to take into account all relevant and available evidence when formulating an argument.

Fallacy of Exclusion

An inductive mistake occurring when relevant available evidence is omitted, particularly evidence that would weaken or alter the conclusion.

Defeater

Additional evidence or information that weakens, undercuts, or undermines an argument's support.

Rebutting Defeater

A defeater that provides direct evidence demonstrating that the conclusion is false.

Undercutting Defeater

A defeater that attacks the logical link between premises and conclusion without necessarily proving the conclusion false.

Inductive Generalization

An inductive argument that uses data gathered from an observed sample to reach a broader conclusion about an entire population.

Representativeness Heuristic

A mental shortcut in which one estimates probability based on how closely an item resembles a typical example or stereotype.

Availability Heuristic

A mental shortcut in which probability is estimated by the ease with which relevant examples come to mind.

Argument from Analogy

An argument that compares items sharing observed similarities to conclude they likely share an additional unobserved characteristic.

Inference to the Best Explanation

An inductive method of reasoning that evaluates competing hypotheses and adopts the one that best accounts for the observed evidence.

Confirmation Bias

The cognitive tendency to seek out, notice, and accept evidence supporting prior beliefs while ignoring or downplaying contrary evidence.

Disconfirmation Bias

The cognitive tendency to scrutinize counter-evidence far more critically than evidence that aligns with existing beliefs.

Fallacy of Equivocation

A fallacy that occurs when a single word or phrase is used with two different meanings within the same argument.

Confound

An extraneous variable that influences two variables simultaneously, creating the misleading appearance of a direct causal link.

JTB Theory of Knowledge

The traditional epistemological account defining knowledge as Justified True Belief.

Gettier Problem

A philosophical critique demonstrating that justified true belief is insufficient for knowledge because a belief can be justified and true purely by luck.

A Priori Justification

Epistemic justification that does not depend on sensory observation or empirical experience, relying instead on pure reason or conceptual understanding (e.g., $2 + 2 = 4$).

A Posteriori Justification

Epistemic justification that depends directly on empirical experience or sensory observation.

Testimonial Evidence

Information or knowledge acquired through the reports, statements, or testimony of other people.