Abstract and Concrete
Abstract and Concrete.
Contrasting terms in traditional philosophy and grammar, concrete referring to the material and specific, abstract to the ideal and general. Abstraction as a mental process starts with many particular things or events and moves to a single generality within or behind them, such as the concept time abstracted from such changes as day and night, the seasons, and ageing. In grammar, an abstract noun refers to an action, concept, event, quality, or state (love, conversation), whereas a concrete noun refers to a touchable, observable person or thing (child, tree). This semantic classification cuts across the syntactic division countable/uncountable noun. Although abstract nouns tend to be uncountable (courage, happiness, news, tennis, training), many are countable (an hour, a joke, a quantity). Others can be both, often with shifts of meaning from general to particular (great kindness/many kindnesses; not much industry/a major industry).