The Cat in the Hat circumstances" which is soon enhanced by make believe. The book starts in a factual, realistic world, which crosses over into the world of make believe with the loud bump that heralds the arrival of the Cat. However, this is the first Dr. Seuss book in which the fantasy characters, i.e. the Cat and his companions, are not products of the children's imagination. It also differs from previous books in that Sally and her brother actively participate in the fantasy world; they also have a changed opinion of the Cat and his world by the story's end. Ruth MacDonald asserts, ""The
The Cat in the Hat read, and Spaulding provided Geisel with a similar list. Geisel later told biographers Judith and Neil Morgan that Spaulding had supplied him with a list of 348 words that every six-year-old should know and insisted that the book's vocabulary be limited to 225 words. However, according to Philip Nel, Geisel gave varying numbers in interviews from 1964 to 1969. He variously claimed that he could use between 200 and 250 words from a list of between 300 and 400; the finished book contains 236 different words. Geisel gave varying accounts of how he conceived of "The Cat in the Hat".