CHAPTER 7.
LOGICAL DIVISION AND CLASSIFICATION.

1. NATURE OF LOGICAL DIVISION.

The term genus is used for any class name which stands for two or more subordinate classes while the term species is made to stand for any one of the subordinate classes.

The proximate genus of any species is the next class above. For example the proximate genus of man is biped, not animal.

Logical division is the process of separating a proximate genus into its co-ordinate species.

ILLUSTRATIONS:

Genus Species
(1) Heavenly bodies Fixed stars
Planets
Satellites
Comets
Meteors
Nebulae
(2) Vertebrates Leptocardians
Fishes
Amphibians
Reptiles
Birds
Mammals
(3) Man Caucasian
Mongolian
Malay
Ethiopian
American Indian
(4) Government Monarchy
Aristocracy
Democracy

2. LOGICAL DIVISION DISTINGUISHED FROM ENUMERATION.

When the genus is separated at once into individual objects the process is not logical division, but simple enumeration. Logical division implies a separating into smaller class terms, each term being a genus of still smaller subdivisions. This process may be continued till the last division gives individuals as species. Enumeration takes place when the first subdivision results in a list of individuals. To illustrate:

Logical Division.
Teacher Science teacher
Mathematics teacher
English teacher
Modern language teacher
Enumeration.
Teacher John J. Brown
H. G. White
Mary Jones
Alice Smith