Tip 5 - Introduce each paragraph with a topic sentence.

In my Introduction to these Top 10 Tips, I wrote that you must have a clear idea of the writing's purpose before you set pen to paper or hands to keyboard. Each paragraph of your document must further that purpose, and in turn, each topic sentence must contain the general idea of the paragraph. That is the job of the topic sentence: to make a claim that supports the goals of your writing and unify the information that follows, which should describe, prove, or give examples of that claim. If you do that, then you just may achieve the perfect paragraph.

In legal writing, topic sentences are usually first in a paragraph or immediately follow a transitional sentence (more to come on transitions next week). The reason for putting the topic sentence at the beginning is to provide readers with an overview of the information you are about to present, and by doing so, the readers are better able to absorb the content because they already know its context. You never want to leave your readers guessing as to the conclusion you're making. That may work for thriller novels but not for legal writing.

Each topic sentence should contain only one main idea. It is important to keep this rule in mind - one point per paragraph. When you see yourself start to change focus, then it's time for a paragraph break. You should not break up your paragraphs because you have too many or two few sentences, or even because you just have a feeling, as I've been told by a number of clients. You should do so because you have another claim to make.

Strong topic sentences can also help ensure that you've organized your document in the best way possible. A former professor taught me this trick: When editing a text for structure, highlight each topic sentence and then simply read them in order. By doing so, you can better check to see whether your ideas flow from one to another, and if you've effectively organized your text going from the general to the specific and most important to least important.

The Elements of Style contains the best example I've found on the function of a topic sentence and how the rest of the information in the paragraph relates to it. Here Professor Strunk breaks up a paragraph and comments on the role of each sentence.

1 It was chiefly in the eighteenth century that a very different conception of history grew up.	1 Topic sentence.
2 Historians then came to believe that their task was not so much to paint a picture as to solve a problem; to explain or illustrate the successive phases of national growth, prosperity, and adversity.	2 The meaning of the topic sentence made clearer; the new conception of history defined.
3 The history of morals, of industry, of intellect, and of art; the changes that take place in manners or beliefs; the dominant ideas that prevailed in successive periods; the rise, fall, and modification of political constitutions; in a word, all the conditions of national well-being became the subjects of their works.	3 The definition expanded.
4 They sought rather to write a history of peoples than a history of kings.	4 The definition explained by contrast.
5 They looked especially in history for the chain of causes and effects.	5 The definition supplemented: another element in the new conception of history.
6 They undertook to study in the past the physiology of nations, and hoped by applying the experimental method on a large scale to deduce some lessons of real value about the conditions on which the welfare of society mainly depend. - Lecky, The Political Value of History.	6 Conclusion: an important consequence of the new conception of history.