It could simply be a pertinent fact that explicitly illustrates the point you wish to make. If you use a piece of startling information, follow it with a sentence or two of elaboration.
It also needs a final paragraph summarizing what's been said and driving the author's argument home. These are not arbitrary requirements. Introductions and conclusions are crucial in persuasive writing. They put the facts to be cited into a coherent structure and give them meaning. So, begin as a lawyer would, by laying out the facts to the judge in the way you think it will help your client best. Like lawyers in court, you should make an "opening statement in this case, an introduction. All in all, remember these are the last words your reader will hear from you before passing judgment on your argument. Make them as focused and forceful as possible. This work is licensed under a Creative Commons Attribution-No Derivative Works 3.0 United States License. Writing Guide: Introduction and Conclusion, damen, 2002 24. Introduction and Conclusion. These represent the most serious omission students regularly make. Every essay or paper designed to be persuasive needs a paragraph at the very outset introducing both the subject at hand and the thesis which is being advanced.
Nor is a history paper an action movie with exciting chases down dark corridors where the reader has no idea how things are going to end. In academic writing it's best to tell the reader from the outset what your conclusion will be.