Writing the Comparison and Contrast Essa…

To compare is to explain the similarities between things; to contrast is to describe their differences. These are the two sides of a single coin. Comparison and contrast both emphasize apparent traits, seeing that which is similar and different. Some argue that the essential nature of human thought itself is the process of recognizing similarities and differences between phenomena (Lakoff and Johnson, Metaphors We Live By). Undoubtedly, comparison and contrast is an essential feature of many rhetorical modes, finding allowing us to describe things, to define things, to analyze things, to make an argument — to do, in fact, almost any kind of writing.

When writers compare and/or contrast two phenomena, like Shakespearean and Italian sonnets, for example, most writers structure their essays one of four ways.

1. First they compare, then contrast (or vice versa).
2. First they describe one trait; then the other.
3. They write about the comparable and contrastable elements of each idea.
4. They only compare or only contrast, not both.

Comparison and contrast may be the primary method of development for an entire essay, but they might also be used as the method of development within a single paragraph as well. Below are two paragraphs (really the same paragraph written twice with slightly different comparison patterns of development) about car ownership. The first is organized by listing the pros first and the cons second, the alternating pattern of comparison. The second paragraph presents the pros and cons side by side in succession. Both work. The use of a transitional device (such as "On the other hand...") is very important to signal the shift in this pattern of comparison.

1. The "First they compare, then contrast" pattern:
   
   To be able to drive is undoubtedly a useful accomplishment, and the ownership of a car is for many a fact of life that reaches beyond convenience to sheer necessity. Furthermore, the owner has the privilege of travelling in door-to-door comfort, the freedom of deciding when he will travel, the value of time saved, and (if he cares for such things) the pride and joy of property. On the other hand, all possessions are a burden, and a car may rank among the heaviest. It is expensive to maintain; it makes the owner a prey to vandals, thieves, and friends who need rides. Finally, cars expose their owners to the risk of accident.

2. The "First they describe one trait; then the other" pattern:
   
   To be able to drive is undoubtedly a useful accomplishment, and the ownership of a car is for many a fact of life that reaches beyond convenience to sheer necessity. On the other hand, all possessions are a burden, and a car may rank among the heaviest. It is expensive to maintain; it makes the owner a prey to vandals, thieves, and friends who need rides. Cars expose their owners to the risk of accident. Against these considerations, the owner has to weigh the privilege of travelling in door-to-door comfort, the freedom of deciding when he will travel, the value of time saved, and (if he cares for such things) the pride and joy of property.

Why a writer might choose one pattern of comparison over another depends, it seems to me, on the overall length of the comparison. If the writer is to compare a only a few points, then a "First they compare, then contrast" pattern works fine. However, if the list of comparable points is huge, then the writer might choose the "First they describe one trait; then the other" alternating pattern for fear that the reader might not be able to hold all the points about one idea in mind before getting to the second (or third) idea in the comparison. In such situations, a side-by-side, alternating pattern seems to work better. Of course, terms like "few" and "huge" above are indefinite and depend on the writer's judgment about what the audience is best able to understand.