By pointing out weaknesses in your presentation, you undermine your essay’s effectiveness. Pointing out limitations or areas for further study can be a useful strategy, however.
If you restate your main point, do so in a fresh way.
You will not be able to discuss new ideas or issues adequately, and they are likely to draw attention from your main points.
Keep your conclusions within the limits of the evidence and explanations you provided in the essay.
*From Simon and Schuster Quick Access Reference for Writers, Second Edition. Ed. Troyka, Lynn Quitman. Upper Saddle River, NJ: Prentice-Hall. 1995.