Paragraph Unity and Coherence
Paragraph unity is the most important characteristic of a good paragraph. It defines that all sentences in a paragraph should speak about one single idea or one main subject. That is, the topic sentence, the supporting details, and the concluding sentence should focus on only one idea. Further, paragraphs should also be coherent. Coherence demands that the ideas or sentences presented in a paragraph should flow smoothly from one to the other. Paragraphs should not only be well-developed and unified but also coherent. In this lesson you will learn about paragraph unity and coherence without which a paragraph cannot be called a complete composition.
What is a paragraph?
A paragraph is the basic unit of composition. It consists of a group of related sentences that develop one main idea. It has three main parts; an introduction, a body of the paragraph and a conclusion. In other words, it has a topic sentence, a few supporting sentences, and a concluding sentence.
What is unity in a paragraph?
Unity in a paragraph means that the entire paragraph should focus on one single idea. The supporting details should explain the main idea. The concluding sentence should end the paragraph with the same idea. Thus, a unified paragraph presents a thought, supports it with adequate details and completes it with a conclusion.
What is coherence in a paragraph?
Coherence means establishing a relationship between the ideas presented in a paragraph. It brings about a rationale in the arrangement of the ideas which are introduced either in the chronological order or in the order of importance. Besides, transitions that compare, contrast, illustrate, add or show cause and effect build logical bridges. The ideas, thus expressed in the paragraph, flow smoothly from one to the other in a logical sequence. This helps the reader to understand the paragraph.
Let us now analyze our model paragraph for unity and coherence:
(1) The human body is a wonderful piece of work that nature has created. (2) It is not beautiful like the body of a butterfly or peacock but it is shaped practically. (3) It can do many types of work which other animals cannot. (4) It is not strong like the body of a tiger. (5) But in place of physical strength it has a big and sharp brain. (6) By using this brain the human physique has been able to overcome many of its limitations. (7) By sitting in an aeroplane it flies faster than a kite, by riding a motorcycle it travels faster than a leopard, and by firing a machine gun it fights much better than a tiger. (8)In spite of all this, the human body suffers from many diseases because it has a weakness for habits such as smoking, drinking and overeating. (9) When it is healthy the body can give great pleasure but when it is sick it can cause great pain. (10) The wise man would always keep his body fit because a healthy mind can work only in a healthy body.
The first sentence states the main idea of the paragraph and claims the superiority of the human body over the rest of the creation. It enables the reader to expect the following ideas in the paragraph that explain and illustrate the qualities and attributes of the human body.
The second, third, fourth, fifth, sixth, and seventh sentences compare, contrast, elucidate and justify the main idea or topic sentence. They establish the main theme with logical explanations and transitions. They create a graphic picture in the minds of the reader with suitable and appropriate language expressions. In brief, they develop the main idea of the paragraph.
The eighth and the ninth sentences interpret and analyze the limitations of the human body and prove the strength of the topic sentence. They, further, lead the main idea into a concluding thought.
Finally, the tenth sentence concludes with the idea that the human body should be well preserved for a proper functioning of the system and that a healthy mind can work only in a healthy body.

Thus the paragraph, The Human Body, is a unified and coherent paragraph.