re 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.

Partition. In non-scientific compositions such completeness is seldom
necessary. It might even defeat the purpose by being too involved, by
including too many entries, and by becoming difficult to remember.
Speakers seldom have need of classification, but they often do have
to make divisions for purposes of explanation. This kind of grouping
is called partition. It goes only so far as is necessary for the
purpose at the time. It may stop anywhere short of being complete and
scientifically exact. All members of the large class not divided and
listed are frequently lumped together under a last heading such as
_all others, miscellaneous, the rest, those not falling under our
present examination_.

EXERCISES

1. Classify games. Which principle will you use for your first main
division--indoor and outdoor games, or winter and summer games, or
some other?

2. Classify the races of men. What principle would you use?

3. How would you arrange the books in a private library?

4. Classify the forms of theatrical entertainments. Is your list
complete?

5. Classify branches of mathematics. The entries may total over a
hundred.

6. Classify the pupils in your school.

7. Classify the people in your school. Is there any difference?

8. Classify the following:

The political parties of the country.
Methods of transportation.
Religions.
Magazines.
The buildings in a city.
Aircraft.
Desserts.
Canned goods.

Skill in division is valuable not only as a method of exposition but
it is linked closely with an effective method of proving to be
explained in the next chapter--the method of residues. Can you recall
any extracts given in this book in which some form of division is
used? Is this form of material likely to be more important in
preparation or in the finished speech? Explain your opinion--in other
words, present a specimen of exposi