The Categorical Imperative is supposed to provide a way for us to evaluate moral actions and to make moral judgments. It is not a command to perform specific actions -- it does not say, follow the 10 commandments, or respect your elders.
A blurb on a book can be any combination of quotes from the work, the author, the publisher, reviewers or fans, a summary of the plot, a biography of the author or simply claims about the importance of the work.
WordReference Random House Learner's Dictionary of American English Â© 2017. blurb /blÉrb/USA pronunciation n. [countable] a brief notice that describes a book, play, etc., esp. one full of praise:The blurb on the book jacket promised action, thrills, adventure, and romance.''.