Critical Thinking by Example

Example 1.7: Linked Argument [1] Lassie is a mammal, [2] since Lassie is a dog, [3] and all dogs are mammals. 1 2 3 Notice how in a linked argument the premises must work together to support the conclusion. [3] on its own does not support the conclusion without the knowledge that Lassie is a dog, and [2] does not support the conclusion without the knowledge that dogs are mammals. So, [2] and [3] need each other to provide any reason to believe the conclusion. Example 1.8: Convergent Argument [1] Lassie is a great pet [2] because she is smart [3] and she scares away intruders. 1 2 3 Notice that both [2] and [3] on their own provide some reason to believe the conclusion. The two independent reasons converge on the same conclusion. Example 1.9: Divergent Argument [1] Lassie is a dog [2] so she needs regular walks and [3] an occasional good brushing. 2 3 1 Premise [1] is offered in support of two distinct conclusions: [2] and [3]. You may want to try the chapter exercises: http://www.criticalthinkingbyexample.com/Chapter1/chapter1.html