Division
One of these methods is by division. A speaker may separate a topic or term into the parts which comprise it. For instance, a scientist may have to list all the kinds of electricity; a Red Cross instructor may divide all bandages into their several kinds; an athletic coach may have to explain all the branches of sports in order to induce more candidates to appear for certain events; a banker may have to divide financial operations to make clear an advertising pamphlet soliciting new lines of business, such as drawing up of wills.
The ability to do this is a valuable mental accomplishment as well as an aid to speaking. In dividing, care must be taken to make the separations according to one principle for any one class. It would not result in clearness to divide all men according to height, and at the same time according to color.
This would result in confusion. Divide according to height first, then divide the classes so formed according to color if needed—as might be done in military formation. Each group, then, must be distinctly marked off from all other groups. In scientific and technical matters such division may be carried to the extreme limit of completeness. Complete division is called classification.