According to Thomas and Turner, there are three kinds of hedges that classic prose avoids:
(1) Hedges of process. Those are "hesitations and uncertainties that arise because one is in the middle of a thought" (38). I don't use those much myself. In written work, they seem artificial, because the reader assumes you have revised your prose.
(2) Hedges of liability. These are expressions like "as far as I have been able to determine." I don't think academic prose can do without such hedges completely. The careful academic writer must delineate the boundaries and limits of his or her knowledge. A possible way around this hedge is to limit the argument to assertions that one knows with more certainty.
(3) Hedges of worth. Arguments about the inherent value of studying a particular subject. "The classic writer spends no time justifying her project" (39). All my writing, however, betrays an anxiety about the value of what I am studying. While my argument is often implicit, I have to justify why it is an important subject to be writing about in the first place. What I need to do, then, is to make this justification even more implicit, even more inherent in my arguments. Just as the authors of this book, Thomas and Turner, argue for the classic style but never have to justify why it is important to consider the matter in the first place, so my argument on behalf of late modernism must take for granted that we want the richest possible poetics.
As I understand this book, Clear and Simple and the Truth, the authors are not saying that everyone should attempt to write in classic prose, but that every style has an ethos, a set of assumptions about the relationships between readers and writers, language, thought, and truth. They clearly lay out the assumptions of the "classic" model and contrast them with other possible styles. The classic style is a good foil, because it is so absolute and uncompromising, so elegant when it works well.