Arguments favoring the existence of extraterrestrial intelligence nearly always contain an overt appeal to big numbers, often combined with a covert reliance on generalization from a single instance. In this paper I examine both motifs, and consider whether big numbers might actually make palatable otherwise implausible single-case inductions. In the end, the dispute between believers and skeptics is seen to boil down to a conflict of intuitions which can barely be engaged, let alone resolved, given our present state of knowledge.