Useful Deductively Valid Argument Phi101 All Whal

For your assignment , you need to read my class lecture Notes (both shorter and longer) from the content area. Shorter might be more help for your assignment.

1. I have provided you with a handout on a list of useful deductively valid argument patterns (the file is called PHL (Valid Arguments or something like that). There are infinitely many such valid (hereafter I will drop deductive) patterns. I have simplified your life. You need to know that list. For our course, it will be good enough.

2. Good news is that I won’t ask you anything about the soundness or how strong/weak an argument is. So for your assignment, only confine your attention to the deductive validity of an argument.

3. In your assignment when I ask you to test the validity of the following arguments, I mean “deductively validity” and nothing else.

4. How to test them? In your assignment, I will allow you to adopt a mechanical way to test them. If an argument matches any of the patters from the list then call it “valid”. If it does not match any of the patterns then brand it as “invalid”. If it does not match any of the patters, then one way to show that it is invalid is to produce a counter-example. But, for this course, if you just say that the argument in question in invalid since it does it agree with any of the structures from the list then you will be fine. However, here is a proviso.

5. You might find an argument of the following structure, e.g.,

I walk. Therefore, I exist.

This argument does not apparently match any of the patters from your handout. But, in fact, it does match one of the patterns because it requires a suppressed premise of the form “If I walk then I exist.” Once that premise has been supplied then the entire argument would be of the form:

a. I walk

b. If I walk then I exist.

Therefore, I exist.

Now the argument is valid and follows the structure 1 of your handout. Please be on the look-out for such an argument in your assignment. For arguments like them, you need to provide a premise to make the argument valid.

QUESTIONS ARE IN THE “PHIL 101(Q1)” DOCUMENT