Evaluating Arguments

1. are clear about the nature of the argument under examination;

2. focus your thinking on the most interesting and controversial steps in the argument; and

3. make some progress toward finding the truth, or at least identifying exactly why you agree or disagree with the author's argument.
   STEP 1: Identify the conclusion of the argument. Sometimes that is more difficult than it at first appears. Note that how you phrase the conclusion can be very important in how you develop the premises supporting it. You may find that as you try to identify premises you change your mind about what the conclusion is or how to phrase it. That is fine.

   STEP 2: Identify the stated premises mentioned by the author in support of the conclusion. These are the reasons the author gives for believing his or her conclusion. Try to rephrase these as necessary to clarify the points, make them more precise, and fit each premise with the other premises and with the conclusion. List the premises before the conclusion and number them sequentially.

   STEP 3: Identify any unstated premises or assumptions that are necessary in order that the stated premises actually provide support for the conclusion. Try to phrase these assumptions in a sympathetic way, as you might imagine the author would phrase them.

   STEP 4: Evaluate whether the premises provide reasonable support for the conclusion.

   • Inductive Arguments: If the premises are supposed to provide evidence or support but not conclusive proof of the conclusion, evaluate whether the premises, if true, would actually provide support for the conclusion and how strong you think the support would be (e.g. in light of contrary evidence).

   • Deductive Arguments: If the premises are supposed to provide conclusive proof of the conclusion, evaluate whether the argument is valid or invalid.
     • Valid: it is impossible for the conclusion to be false if all the premises were true

     • Invalid: this is not impossible

     • Tests: 1) Ask yourself: can you imagine it? 2) Check for formal validity.

     • If you decide a deductive argument is invalid, change it to make it valid, adding premises as necessary. Then go to Step 5.

   • STEP 5: Evaluate whether the premises are true or false. Is there reason to question one of the premises? What could the author say in defense of the premise?

   • RECURSION STEP (Optional): If one premise is especially important to evaluating the argument, go back to Step 1 and take that premise as a conclusion, looking for a further argument in support of it, and then evaluating that further argument. This then could lead to another recursion to evaluate another premise, and so on until all questions are resolved and the truth has become transparent to all!
   
   
   
   
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