How Do You Recognize The Modus Ponens Argument Form?
An argument form is simply a pattern of reasoning. To think critically, you must be able to recognize this argument form. Consider the following two arguments: Argument #1: 1. If Lassie is a Collie, then Lassie is a dog. 2. Lassie is a Collie So, 3. Lassie is a dog. Argument #2: 1. If Barack Obama is a U.S. president, then Barack Obama is a U.S. citizen. 2. Barack Obama is a U.S. president. So, 3.Barack Obama is U.S. citizen. In each case, lines 1 and 2 are the premises, and line 3 is the conclusion. Both of these arguments are valid, and it is necessary that, if the premises are true, then the conclusion is true. Both of these arguments also have the same argument form. This particular form of reasoning is so conventional that logicians have given it a special name: MODUS PONENS. MODUS PONENS means “the way or mode of positing”. Notice that in each of the arguments, the second premise posits or affirms the if-part of the first premise. This pattern of reasoning can be represented as f
