Philosophy
361:
Practice With Validity |
Using the definitions of 'deductive', 'inductive', 'valid', 'invalid', 'sound', 'unsound', 'strong', and 'weak' given in class, indicate whether the following are true or false.
Relying on your natural sense of what follows from various statements and your commonsense knowledge of the world, determine for each of the following arguments (1) whether the premises are true, (2) whether the argument is valid or invalid and (3) whether the argument is sound or unsound.
3. P1 is false (e.g. scrubbing toilets may be offensive, but it's not immoral). P2 is true, C is false (though controversial). Valid (because IF the premises WERE true, the conclusion would have to be true - this is an example of the valid argument form affirming the antecedent). Unsound, because P1 is false.
4. P1 & C are true. Invalid (The fact that some Albanians hail from Albania does not make it true that wealthy ones do. Even if some Albanians hailed from Albania, it could have been the case that all the wealthy ones hailed from some other country). Unsound, because the argument is invalid.
5. P1, P2 & C are true. Invalid (The premises say nothing about whether the Reds or the Cardinals are baseball teams, so it could have been the case that both premises were true yet the Reds and the Indians were soccer teams). Unsound, because the argument is invalid.
6. P1 & C are true, P2 is false. Valid (because IF the premises WERE true, the conclusion would have to be true). Unsound (because P2 is false).
361 Home page
Dr. Korcz's Home Page