Logic in a Nutshell

Exercise L3:  Identifying Argument Forms

 

 

Instructions:  Identify the underlying basic argument form of the the following examples, and explain whether the arguments are valid or invalid.   Please note that an answer key has been provided for Part A.

 

 

Part A:  Practice Questions

 

  1. Either he is a damned liar or he is completely nuts.  Well he sure as hell ain't nuts, so he must be a liar.

  2. If you like working with the Boy Scouts, then you've gotta like camping out.  And you know how much you like camping out.  So you'll go for the Boy Scouts.

  3. If you spend a few hours a week taking care of your equipment, it won't get rusty. if it doesn't, you will have it for the rest of your life.  So if you take care of your equipment, you will have it for the rest of you life.

  4. If you like working with the Boy Scouts, then you've gotta like camping out.  But you know how much you hate camping out.  So the Boy Scouts isn't for you.

  5. If construction begins before July 4th, then the building will be ready to be occupied before Winter.  Construction will definitely begin before July 4th, and so therefore, we can expect to occupy the building before Winter.

  6. Ladies and gentle of the jury:  If a person was sane, he would not go around killing dozens of innocent women.  Theodore Bundy killed dozens of innocent women.  Therefore, he can hardly be considered sane, now can he?

 

 

  Answer Key for Practice Questions

 

 

Part B:  Homework Assignment

 

  1. Extremism in defense of liberty is always a vice---because extremism is but another name for fanaticism which is a vice by definition.

  2. If then, it  is agreed that things are either the result if coincidence or for an end, and things cannot be the result of coincidence or spontaneity, it follows that they must be for and end.  (Aristotle)

  3. Either wealth is an evil or wealth is a good; but wealth is not an evil; therefore wealth is a good. (Sextus Empiricus)

  4. Since them to fight against neighbors is an evil, and to fight against the Thebans is to fight against neighbors, it is clear that to fight against the Thebans is an evil.  (Aristotle)

  5. Also, what is simple cannot be separated from itself.  The  soul is simple, therefore, it cannot be separated from itself.  (Duns Scotus)

  6. If each man has a definite set of rules of conduct by which he regulated his life, he would be no better than a machine.  But there are no such rules, so men cannot be machines.

  7. If error was something positive, God would be its cause, and by Him it would continually be procreated.  But this is absurd.  (Spinoza)

  8. If the North Koreans are smart---and we know they are smart---they will move in the direction of reform.