 We have a conflict between the following two arguments (where arguments are sequences of inferences): Penguin \(\Rightarrow\) Bird \(\rightarrow\) flies and Penguin \(\rightarrow\) not-flies. Both arguments include a final defeasible inference. What is important to notice is that a penguin is a specific type of bird since Penguin \(\Rightarrow\) Bird (while not Bird \(\Rightarrow\) Penguin). According to the Specificity Principle an inference with a more specific antecedent overrides a conflicting defeasible inference with a less specific antecedent. Concerning the penguin Tweety we thus infer that she doesn’t fly on the basis of Penguin \(\rightarrow\) not-flies rather than that she flies on the basis of Penguin \(\Rightarrow\) Bird \(\rightarrow\) flies. 