The thesis should guide in the course of essay writing. Certainly you will acquire new information and ideas as you go along but the thesis should serve you as one of the starting points. This is why you often cannot finish your thesis statement until you finish your essay. Why Write a Thesis Statement? Why should you write a thesis statement when you write an essay? Most essays don't completely succeed for all readers. Havi. The decision as to whether to do so should be based on what will work best with your subject and your readers. However, the tradition of putting the thesis in the first paragraph has led some students to mistakenly think of the thesis statement as a kind of introduction to the essay. Do not use periods / full stops (.) at the end or capital letters at the beginning of the phrases you write. You can see an example. Click the "Build a Thesis" button when you're finished. Seeing the relationship between your thesis statement and your essay. How to Write a Thesis Statement Ask and answer the questions "why?" and "how?" of your trial thesis statement. Make your thesis statement a positive statement, not a negative one. I will often ask you to write a "trial thesis statement" before submitting a draft of your essay; the term "trial" means that this is not a thesis statement you are committed to. Your thesis statement might appear in the first paragraph, or the last paragraph, or it might not appear in the essay at all. I do not mean by a thesis statement something that you necessarily write before writing the essay.