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.
Blurbs are the second most important selling tool you have for your book, so you want it to grab the reader's attention. Your novel is hundreds of pages long, but you'll need to describe it in a few short paragraphs.