Generalization, or Conception, is that faculty of the mind by which we are able to combine and group together several particular ideas into one general idea. Thus when we find a number of particular objects possessing the same general qualities, attributes or properties, we proceed to classify them by the process of Generalization. For instance, in a number of animals possessing certain general and common qualities we form a concept of a class comprising those particular animals. Thus in the concept of cow, we include all cows—we know them to be cows because of their possession of certain general class qualities which we include in our concept of cow. The particular cows may vary greatly in size, color and general appearance, but they possess the common general qualities which we group together in our general concept of cow. Likewise by reason of certain common and general qualities we include in our concept of "Man," all men, black, white, brown, red or yellow, of all races and degrees of physical and mental development. From this generic concept we may make race concepts, dividing men into Indians, Caucasians, Malays, Negroes, Mongolians, etc. These concepts in turn may be divided into sub-races. These sub-divisions result from an analysis of the great concept. The great concept is built up by synthesis from the individuals, through the sub-divisions of minor concepts. Or, again, we may form a concept of "Napoleon Bonaparte" from the various qualities and characteristics which went to make up that celebrated man.
The product of Generalization or Conception is called a Concept. A Concept is expressed in a word, or words, called "A Term." A Concept is more than a mere word—it is a general idea. And a Term is more than a mere word—it is the expression of a general idea.
A Concept is built up from the processes of Perception, Abstraction, Comparison and Generalization. We must first perceive; then analyze or abstract qualities; then compare qualities; then synthesize or classify according to the result of the comparison of qualities. By perceiving and comparing the qualities of various individual things, we notice their points of resemblance and difference—the points wherein they agree or disagree—wherein they are alike or unlike. Eliminating by abstraction the points in which they differ and are unlike; and, again by abstraction, retaining in consideration the points in which they resemble and are alike; we are able to group, arrange or classify these "alike things" into a class-idea large enough to embrace them all. This class-idea is what is known as a General Idea or a Concept. This Concept we give a general name, which is called a Term. In grammar our particular ideas arising from Percepts are usually denoted by proper nouns—our general ideas arising from Concepts are usually denoted by common nouns. Thus "John Smith" (particular; proper noun) and "Man" (general; common noun). Or "horse" (general; common), and "Dobbin" (particular; proper).
It will be seen readily that there must be lower and higher concepts. Every class contains within itself lower classes. And every class is, itself, but a lower class in a higher one. Thus the high concept of "animal" may be analyzed into "mammal," which in turn is found to contain "horse," which in turn may be sub-divided into special kinds of horses. The concept "plant" may be sub-divided many times before the concept "rose" is obtained, and the latter is capable of sub-division into varieties and sub-varieties, until at last a particular flower is reached. Jevons says: "We classify things together whenever we observe that they are like each other in any respect and, therefore, think of them together.... In classifying a collection of objects, we do not merely put together into groups those which resemble each other, but we also divide each class into smaller ones in which the resemblance is more complete. Thus the class of white substances may be divided into those which are solid and those which are fluid, so that we get the two minor classes of solid-white, and fluid-white substances. It is desirable to have names by which to show that one class is contained in another and, accordingly, we call the class which is divided into two or more smaller ones, the Genus; and the smaller ones into which it is divided, the Species."
Every Genus is a Species of the class next higher than itself; and every Species is a Genus of the classes lower than itself. Thus it would seem that the extension in either direction would be infinite. But, for the purposes of finite thought, the authorities teach that there must be a Highest Genus, which cannot be the Species of a higher class, and which is called the Summum Genus. The Summum Genus is expressed by terms such as the following: "Being;" "Existence;" "The Absolute;" "Something;" "Thing;" "The Ultimate Reality," or some similar term denoting the state of being ultimate. Likewise, at the lowest end of the scale we find what are called the Lowest Species, or Infima Species. The Infima Species are always individuals. Thus we have the individual at one end of the scale; and The Absolute at the other. Beyond these limits the mind of man cannot travel.
There has been much confusion in making classifications and some ingenious plans have been evolved for simplifying the process. That of Jevons is perhaps the simplest, when understood. This authority says: "All these difficulties are avoided in the perfect logical method of dividing each Genus into two Species, and not more than two, so that one species possesses a particular quality, and the other does not. Thus if I divide dwelling-houses into those which are made of brick and those which are not made of brick, I am perfectly safe and nobody can find fault with me.... Suppose, for instance, that I divide dwelling-houses as below:
| Dwelling-House | ||||
| | | ||||
| | | | | | | | | | |
| Brick | Stone | Earth | Iron | Wood |
"The evident objection will at once be made, that houses may be built of other materials than those here specified. In Australia, houses are sometimes made of the bark of gum-trees; the Esquimaux live in snow houses; tents may be considered as canvas houses, and it is easy to conceive of houses made of terra-cotta, paper, straw, etc. All logical difficulties will, however, be avoided if I never make more than two species at each step, in the following way:—
| Dwelling-House | |||||||||||||||||||||||
| Brick | Not-Brick | ||||||||||||||||||||||
| Stone | Not-Stone | ||||||||||||||||||||||
| Wooden | Not-Wooden | ||||||||||||||||||||||
| Iron | Not-Iron | ||||||||||||||||||||||
"It is quite certain that I must in this division have left a place for every possible kind of house; for if a house is not made of brick, nor stone, nor wood, nor iron, it yet comes under the species at the right hand, which is not-iron, not-wooden, not-stone, and not-brick.... This manner of classifying things may seem to be inconvenient, but it is in reality the only logical way."