Nativists inspired by Chomsky are apt to provide arguments with the following general form: languages exhibit interesting generalizations that are not suggested by casual (or even intensive) examination of what people actually say; correspondingly, adults (i.e., just about anyone above the age of four) know much more about language than they could plausibly have learned on the basis of their experience; so absent an alternative account of the relevant generalizations and speakers' (tacit) knowledge of them, one should conclude that there are substantive "universal" principles of human grammar and, as a result of human biology, children can only acquire languages that conform to these principles. According to Pullum and Scholz, linguists need not suppose that children are innately endowed with "specific contingent facts about natural languages." But Pullum and Scholz don't consider the kinds of facts that really impress nativists. Nor do they offer any plausible acquisition scenarios that would culminate in the acquisition of languages that exhibit the kinds of rich and interrelated generalizations that are exhibited by natural languages. As we stress, good poverty-of-stimulus arguments are based on specific principles - - confirmed by drawing on (negative and crosslinguistic) data unavailable to children -- that help explain a range of independently established linguistic phenomena. If subsequent psycholinguistic experiments show that very young children already know such principles, that strengthens the case for nativism; and if further investigation shows that children sometimes "try out" constructions that are unattested in the local language, but only if such constructions are attested in other human languages, then the case for nativism is made stronger still. We illustrate these points by considering an apparently disparate -- but upon closer inspection, interestingly related -- cluster of phenomena involving: negative polarity items, the interpretation of 'or', binding theory, and displays of Romance and Germanic constructions in child- English...