1911 Encyclopædia Britannica/Concrete
CONCRETE (Lat. concretus, participle of concrescere, to grow together), a term used in various technical senses with the general significance of combination, conjunction, solidity. Thus the building material made up of separate substances combined into one is known as concrete (see below). In mathematics and music, the adjective has been used as synonymous with "continuous" as opposed to "discrete," i.e. " separate," "discontinuous." This antithesis is no doubt influenced by the idea that the two words derive from a common origin, whereas "discrete" is derived from the Latin discernere. In logic and also in common language concrete terms are those which signify persons or things as opposed to abstract terms which signify qualities, relations, attributes (so J. S. Mill). Thus the term "man" is concrete, while "manhood" and "humanity" are abstract, the names of the qualities implied. Confusions between abstract and concrete terms are frequent; thus the word "relation," which is strictly an abstract term implying connexion between two things or persons, is often used instead of the correct term "relative" for people related to one another. Concrete terms are further subdivided as Singular, the names of things regarded as individuals, and General or Common, the names which a number of things bear in common in virtue of their possession of common characteristics. These latter terms, though concrete in so far as they denote the persons or things which are known by them (see Denotation), have also an abstract sense when viewed connotatively, i.e. as implying the quality or qualities in isolation from the individuals. The ascription of adjectives to the class of concrete terms, upheld by J. S. Mill, has been disputed on the ground that adjectives are applied both to concrete and to abstract terms. Hence some logicians make a separate class for adjectives, as being the names neither of things nor of qualities, and describe them as Attributive terms.