Abstraction

Abstraction is that intellectual process by which the mind withdraws some of the attributes of objects from the others, and thinks of them to the exclusion of the rest. The abstract is opposed to the concrete. John, William, my brother, form concrete images in my mind, each with a multitude of attributes peculiar to himself. But they have also certain attributes common to them and to all individuals of the race; I can overlook the others, and attend to these, and thus form a notion or conception, which is called a man. Man is therefore an abstract notion, the word connoting, as it is called, a certain though not very well-defined number of attributes. With the exception of proper names, all nouns are thus abstract. There are degrees, however, in abstraction. The abstract notion animal rises above that of man, embracing all men and innumerable organised beings besides. An organised being, again, is a still higher stage, and embraces both animals and plants. Being, time, space, are among the highest abstractions. Abstraction is the basis of classification into genera and species (see GENERALISATION). The higher abstractions rise, the fewer attributes are implied or connoted in the name. On the other hand, the number of objects to which the name is applicable, increases; and thus reasoning in abstract terms has the advantage of being general, or extensive in its application. But such reasoning is apt to become vague and fallacious, unless constant regard is had to concrete instances.