PhD Doctor of Philosophy Logic, Argumentation, and Philosophy of Language 1 — Questions and Answers
Question 1: A valid deductive argument is one in which:
- If the premises are true, the conclusion must be true (Correct answer)
- The conclusion is probably true given the premises
- The premises provide some support for the conclusion
- The argument is accepted by most experts
Correct answer: If the premises are true, the conclusion must be true
Validity is a formal property: in a valid argument it is impossible for the premises to be true and the conclusion false.
Question 2: The distinction between a priori and a posteriori arguments rests on whether justification depends on:
- Experience or reason alone (Correct answer)
- Formal structure or content
- Deduction or induction
- Universal or particular claims
Correct answer: Experience or reason alone
A priori arguments are justifiable by reason alone without empirical evidence, while a posteriori arguments require observational evidence.
Question 3: Modus ponens is a valid argument form that proceeds from 'If P then Q' and 'P' to conclude:
- Q (Correct answer)
- Not P
- Not Q
- If Q then P
Correct answer: Q
Modus ponens (affirming the antecedent) is: given the conditional and its antecedent, the consequent follows necessarily.
Question 4: An ad hominem fallacy attacks the arguer's:
- Character rather than the argument itself (Correct answer)
- Conclusion rather than premises
- Premises for being false
- Logic for being invalid
Correct answer: Character rather than the argument itself
Ad hominem redirects from the substance of an argument to personal characteristics of the person making it, which is irrelevant to the argument's soundness.
Question 5: Frege's sense/reference (Sinn/Bedeutung) distinction distinguishes between the meaning of a term and its:
- Actual object or referent in the world (Correct answer)
- Psychological image in the mind
- Syntactic role in a sentence
- Pragmatic use in context
Correct answer: Actual object or referent in the world
Frege showed that 'morning star' and 'evening star' have the same reference (Venus) but different senses (modes of presentation), explaining how identity statements can be informative.
Question 6: Russell's theory of definite descriptions analyzes phrases like 'the present King of France' as:
- Quantified existential claims, not referring expressions (Correct answer)
- Direct references to individuals
- Meaningful only if the referent exists
- Synonymous with proper names
Correct answer: Quantified existential claims, not referring expressions
Russell argued 'the F is G' should be analyzed as 'there exists exactly one F, and it is G,' allowing sentences about non-existent entities to be meaningful and false.
PhD Doctor of Philosophy Logic, Argumentation, and Philosophy of Language 1
A valid deductive argument is one in which: