philosophy.lander.edu

Homepage  >  Assessment  >   Logic  >  Question 6       

Philosophy 103: Introduction to Logic
Logic Assessment Pretest Question 6

6. What statement logically follows from the following statement?  Some New York police officers are honest policemen.  a. All New York police officers are honest policemen.  b. No New York police officers are totally honest policemen.  c. Some New York police officers are not honest policemen.  d. Some New York police officers are not dishonest policemen.  e. Some honest policemen are not New York police officers. Purpose for the Question:  One objective of logic is to grasp the features of traditional logic. First, this question is designed to test for an understanding of the logical relation called subcontrariety.  When we know some S is P, sometimes all S is P and other times some S is not P.  E.g.,, with ravens, some ravens are black because all of them are. Thus, one cannot conclude some S is not P will always follows from some S is P, without assuming other information not stated in the passage. Second, this question tests for an understanding of the logical relation called obversion. To obvert a given statement, one changes the quality of the statement (i.e., affirmative or negative) and replaces the predicate term with its complementary class.		Phil 103 02 Archie
		Engl 373 04 Dumont-Poston
		Engl 101 22 Westcott

Answer Choices: 

a. This inductive inference, all New York police officers are honest, although theoretically possible, is not warranted. 

b. This answer is possible if the meaning of the term "honest" shifts, and one assumes that "pure" or complete "honesty" is not possible. If terms cannot be instantiated, we cannot converse.

c. Although some New York police officers might not be honest, this conclusion does not follow logically from the discovery that some New York police officers are honest.    

d.  Statement d logically follows because it is the obverse of the given statement.  Obversion always results in an equivalent statement; hence, answer d is the best.

e. This answer, while probably true on other grounds, does not logically follow from the given statement.

Evaluation:   The answers to this question are is consistent across the disciplines. This type of question quite probably will show a substantial difference in assessment outcomes between logic and other courses when logic students begin to be aware of conversational implication.

Send corrections or suggestions to webmaster@philosophy.lander.edu
Read the disclaimer concerning this page.
11.23.04      © 2004 Licensed under GFDL

Arguments | Language | Fallacies  | Propositions  | Syllogisms  | Translation  | Symbolic