Categorization is the central task of the brain, and reentrant signaling allows the brain to categorize its own categorizations, then recategorize these, and so on. Such a process is the beginning of an enormous upward path enabling ever higher levels of thought and consciousness. Reentrant signaling might be likened to a sort of neural United Nations, in which dozens of voices are talking together, while including in their conversations a variety of constantly inflowing reports from the outside world, bringing them together into a larger picture as new information is correlated and new insights emerge.