The Cat in the Hat use of the term "cat" to refer to jazz musicians. According to Nel, "Even as [Geisel] wrote books designed to challenge prejudice, he never fully shed the cultural assumptions he grew up with, and was likely unaware of the ways in which his visual imagination replicated the racial ideologies he consciously sought to reject." Geisel once called the fish "my version of Cotton Mather", the Puritan moralist who advised the prosecutors during the Salem witch trials. Betty Mensch and Alan Freeman support this view, writing, "Drawing on old Christian symbolism (the fish was an ancient sign of Christianity) Dr. Seuss
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".