- This article is about the concept of abstraction in general. For other uses, please see abstract (disambiguation).
An abstraction is an idea, concept, or word which defines the phenomena which make up the concrete events or things which the abstraction refers to, the referents . Abstractions are sometimes used that have ambiguous referents, for example, "happiness" used as an abstraction, can refer to as many things as there are people and events or states of being which make them happy.
A further example, suppose one attempts to define the term architecture and what it refers to: architecture is more than simply designing safe functional buildings; it involves also an element of creation which aims at elegant solutions to problems of construction and use of space. At its best, it evokes an emotional response in the builders, owners, viewers and users of the building
In philosophical terminology abstraction is the thought process wherein ideas are distanced from objects.
Abstraction uses a strategy of simplification of detail, wherein formerly concrete details are left ambiguous, vague, or undefined; thus speaking of things in the abstract demands that the listener have an intuitive or common experience with the speaker, if the speaker expects to be understood.
For example, lots of different things have the property of redness: lots of things are red. And we find the relation sitting-on everywhere: many things sit on other things. The property of redness and the relation sitting-on are therefore abstract.
Problems begin to arise; however, when we try to define specific rules by which we can determine which things are abstract, and which concrete.
Conceptual schemes for abstraction
Something is often considered abstract if it does not exist at any particular place and time but instances, or members, of it can exist in many different places and/or times (we say that what is abstract can be multiply instantiated).
If however we just say that what is abstract is what can be instantiated, and that abstraction is simply the movement in the opposite direction to instantiation, we haven't explained everything. That makes 'dog' and 'telephone' abstract ideas, but even small children can recognise a dog or a telephone despite their varying appearances in particular cases. You could say that these concepts are abstractions but are not found to be very abstract in a conceptual sense. We can look at the progression from dog to mammal to animal, and see that animal is more abstract than mammal; but on the other hand mammal is a harder idea to express, certainly in relation to marsupial.
Things are often said to be concrete, that is, not abstract, when they have physical existence or when they occupy space.
In general, a concept is considered concrete if it is not abstract: it must be both particular and an individual, and hence occupy both space and time. To say that a physical object is concrete is to say, approximately, that it is a particular individual that is located at a particular place and time.
Abstract things are sometimes defined as those things that do not exist in reality or exist only as sensory experience, like red. The problem begins to arise here when we try to decide which things are, in fact, real. Is God real, or abstract? Even if real, could God also be abstract? Is the number 3 real? Is goodness real, or only its effects, or is it just an abstract idea created by humans?
Abstraction used in philosophy
Abstraction in philosophy is the (oft-alleged) process, in concept-formation , of recognizing among a number of individuals some common feature, and on that basis forming the concept of that feature. The notion of abstraction is important to understanding some philosophical controversies surrounding empiricism and the problem of universals.
Ontological status of abstract concepts
If we say that properties and relations are, or have being, clearly we mean they have a different sort of being from that which physical objects, like rocks and trees, have. That accounts for the usefulness of the word abstract. We apply it to properties and relations to mark the fact that if they exist, they do not exist in space or time, but that instances of them can exist in many different places.
On the other hand the apple and an individual human being are said to be concrete, and particulars, and individuals.
Confusingly, philosophers sometimes refer to tropes, or property-instances (e.g., the particular redness of this particular apple), as abstract particulars .
Reification, also called hypostatization, is usually considered a logical fallacy wherein an abstract concept, such as "society" or "technology" is treated as if it were a concrete thing. It is important to note that reification necessarily occurs linguistically in the English language and many other languages wherein abstract objects are referred to using the same sorts of nouns that signify concrete objects. This can further confuse us about which things are abstract and which concrete, as our language tends to influence us toward reification.
An abstraction can be seen as a process of mapping multiple different pieces of constituent data to a single piece of abstract data based on similarities in the consituent data, for example many different physical cars map to the abstraction "automobile". This conceptual scheme emphasizes the inherent equality of both constituent and abstract data, thus avoiding problems arising from the distinction between "abstract" and "concrete". In this sense the process of abstraction entails the identification of similarities between objects and the process of associating these objects with an abstraction (which is itself an object). Chains of abstractions can therefore be constructed moving from neural impulses arising from sensory perception to basic abstractions such as color or shape to experiential abstractions such as a specific car to semantic abstractions such as the "idea" of an automobile to classes of objects such as "machines" and even categories such as "object" as opposed to "action".
This conceptual scheme entails no specific heirarchical taxonomy (such as the one mentioned involving cars and machines), only a progressive compression of detail.
The neurology of abstraction
Some research into the human brain suggests that the left and right hemispheres differ in their handling of abstraction. One side handles collections of examples (eg: examples of a tree) whereas the other handles the concept itself.
Abstraction in Art
Most typically abstraction is used in the arts as a synonym of Abstract art in general. It can, however, refer to any object or image which has been distilled from the real world, or indeed another work.
- Eugene Raskin, Architecturally Speaking, 2nd edition, a Delta book, Dell (1966), trade paperback, 129 pages
The American Heritage Dictionary of the English Language, 3rd edition, Houghton Mifflin (1992), hardcover, 2140 pages, ISBN 0395448956