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Philosophy 103: Introduction to Logic
Logic Assessment Pretest Question 8

8. Evaluate the following argument.   No college graduates are persons who cannot read well, but all persons who cannot read well are persons who are illiterate, so no college graduates are persons who are illiterate.   a. The argument proves its conclusion, if the premisses are known to be true.  b. The argument does not prove its conclusion even if the premisses are true.  c. The argument is good simply because all the statements are true.  d. The argument is not valid, and the reasoning is flawed because all the statements are false.  e. The argument might be good in some specific cases. Purpose for the Question:  One objective of logic is to grasp the features of traditional logic and to develop the ability to think critically. The argument, as given,  appears to commit the fallacy of the illicit process of the minor term.  However, the major premiss, "All persons who cannot read well are persons who are illiterate" should be considered as a definition rather than a predication. Since the major premiss uses the "is" of identity rather than the "is" of predication, the argument can be considered valid.		Phil 103 02 Archie
		Engl 373 04 Dumont-Poston
		Engl 101 22 Westcott

Answer Choices: 

a. The argument does prove its conclusion. Answer a is the best answer to this question.

b. Answer b would be correct if some illiterate persons were college graduates, but this is ruled out by the premiss, "All persons who cannot read well are persons who are illiterate," considered as a definition.

c. Arguments can have all true statements by coincidence, and the conclusion, although true, does not follow logically from the premisses.

d.  Accurate reasoning depends both upon the structure and grammar of what is said (the validity) and upon the truth of the reasons adduced.  One can argue validly with premisses not known to be true.

e. Logic is a prescriptive discipline and claims consistent applications of its principles.  

Evaluation:   The answers to this question are fairly consistent across the disciplines. If this type of question is retained, one might suppose logic students reach the wrong answer more often than the controls, because they might analyze the argument according to the rule of the syllogism and not notice the meaning of the statements used.  Perhaps, the question in future assessment tests should be simply an example of illicit major.

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