lecture September 8, 2010

# lecture September 8, 2010 - I. Validity A valid argument...

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Unformatted text preview: I. Validity A valid argument has the following properties: IF the premises are true, THEN the conclusion must be true. An argument is valid If and Only If it is not possible for all of its premises to be true and its conclusion false. Rule #1: Validity is a property of an argument's FORM, not its content. (1) All fish swim. (2) All sharks are fish. (3) Therefore, all sharks swim. (X) All particles have mass. (Y) All electrons are particles. (Z) Therefore, all electrons have mass. Rule #1: Validity is a property of an argument's FORM, not its content. 1') All As are Bs. 2') All Cs are As. 3') Therefore, all Cs are Bs. *what is great about the above form is that there is NO way for you to come up with an instance whereby the premises are true and the conclusion is false. A = &quot;fish&quot;, &quot;particles&quot;, &quot;plants&quot; B = &quot;swimming&quot;, &quot;having mass&quot;, &quot;minds&quot; C = &quot;sharks&quot;, &quot;electrons&quot;, &quot;ladders&quot; (Good idea: try to reconstruct the original arguments (about fish, etc) by using the form of the argument and the assigned variable).of the argument and the assigned variable)....
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## This note was uploaded on 09/14/2011 for the course PHIL 1200 taught by Professor Davey during the Fall '08 term at Missouri (Mizzou).

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lecture September 8, 2010 - I. Validity A valid argument...

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