7. CONCRETE AND ABSTRACT TERMS.
A concrete term is a term which denotes a thing; e. g., this man, that tree, John Doe, denote in each case a thing. Man and tree, denote many things. All are concrete.
An abstract term is a term which denotes an attribute of a thing; e. g., whiteness, patience, squareness, are abstract terms.
Such words as red, honest, just, are concrete; while redness, honesty, justice, are abstract.
On first thought it might be inferred that “red” is the name of an attribute just as much as “redness.” This is a mistaken thought, however, as when we use the word red we mean red something—an object which is red in color, not the color itself. For example, in saying the house is red, we refer to the thing that is red, not to the color redness.
Descriptive adjectives, because they describe things, are concrete. They do not alone name qualities of things, hence they are not abstract.