Anyone who has done any serious writing knows that the act of writing is a form of thinking.  Formulating vague ideas and half-articulated concepts into coherent, reasoned, justified, well-defended written arguments is not merely the reporting of thinking but is indeed the very doing of thinking.   Michael Gerson, former policy advisor and chief speech-writer to President George W. Bush, has a nice statement of this view, in an article in the Washington Post defending President Barack Obama’s use of teleprompters, here.  An excerpt:

“For politicians, the teleprompter has always been something of an embarrassing vice — the political equivalent of purchasing cigarettes, Haagen-Dazs and a Playboy at the convenience store.
This derision is based on the belief that the teleprompter exaggerates the gap between image and reality — that it involves a kind of deception. It is true that there is often a distinction between a president on and off his script. With a teleprompter, Obama can be ambitiously eloquent; without it, he tends to be soberly professorial. Ronald Reagan with a script was masterful; during news conferences he caused much wincing and cringing. It is the rare politician, such as Tony Blair, who speaks off the cuff in beautifully crafted paragraphs.
But it is a mistake to argue that the uncrafted is somehow more authentic. Those writers and commentators who prefer the unscripted, who use “rhetoric” as an epithet, who see the teleprompter as a linguistic push-up bra, do not understand the nature of presidential leadership or the importance of writing to the process of thought.
Governing is a craft, not merely a talent. It involves the careful sorting of ideas and priorities. And the discipline of writing — expressing ideas clearly and putting them in proper order — is essential to governing. For this reason, the greatest leaders have taken great pains with rhetoric. Lincoln continually edited and revised his speeches. Churchill practiced to the point of memorization. Such leaders would not have been improved by being “unplugged.” When it comes to rhetoric, winging it is often shoddy and self-indulgent — practiced by politicians who hear Mozart in their own voices while others perceive random cymbals and kazoos. Leaders who prefer to speak from the top of their heads are not more authentic, they are often more shallow — not more “real,” but more undisciplined.
. . .
The speechwriting process that puts glowing words on the teleprompter screen serves a number of purposes. Struggling over the precise formulations of a text clarifies a president’s own thinking. It allows others on his staff to have input — to make their case as a speech is edited. The final wording of a teleprompter speech often brings internal policy debates to a conclusion. And good teamwork between a president and his speechwriters can produce memorable rhetoric — the kind of words that both summarize a historical moment and transform it.”

Anyone (and this includes most everybody in management consulting) who has tried to achieve a team consensus over some issue knows the truth of this last paragraph.   The writing of a jointly-agreed text or presentation enables different views to be identified, to surface, and to be accommodated (or ignored explicitly).   Just as writing is a form of thinking, developing team presentations is a form of group cognition and group co-ordination.