Handout

Assessing Categorical Arguments for Validity

Intuitive Method Edition

Indicate whether the following arguments are valid or invalid. Use the Intuitive Method.

  1. All philosophers are lovers of truth. No lovers of truth are closed-minded people. Thus, no philosophers are closed-minded people. 
  2. No soldiers are rich. No rich persons are poets. Hence, no soldiers are poets. 
  3. No scientists are poets. Some scientists are logicians. Therefore, some logicians are not poets. 
  4. Some actors are sculptors. Some poets are not actors. So, some poets are not sculptors. 

Complete the following arguments in such a way such that each is valid: 

  1. All cats are _______.
  2. Some _______ are pets. 
  3. So, some _______ are _______.

 

  1. All _______ are _______. 
  2. No mammals are _______.
  3. So, no _______ are _______.