Preparing the audience for what one is about to say through conciliating words. This is part of the branch of rhetoric classified as exordium, the introduction of a speech.
From the Greek pro, meaning 'before' and therapeia, meaning 'service'.
If I sought to answer all the criticisms that cross my desk, my secretaries would be engaged in little else in the course of the day, and I would have no time for constructive work. But since I feel that you are men of genuine goodwill and your criticisms are sincerely set forth, I would like to answer your statement in what I hope will be patient and reasonable terms. -- Martin Luther King, Jr., Letter from Birmingham Jail
See also, prodiorthosis