From Objectivism Wiki
A concept is a mental integration of a set of two or more existents, which share the same characteristics. This has the effect of pulling together many existents under one mental unit rather than dealing with many existents individually. While any one existent is composed of many characteristics, concepts abstract away only some of the specific properties of concrete examples. Man creates concepts by understanding relationships of similarity and difference observed between existents; the unit is the Objectivist "bridge between metaphysics and epistemology" (ITOE p. 7). The essential fact which needs to be grasped in creating and acquiring concepts is that every existent has an identity (a nature).
Similarities and differences in an existent's nature, which man perceives, form the basis for assigning the existent to a particular concept. Similarities in terms of commensurable characteristics are the basis for the definition of a concepts, and since concepts stand for two or more concretes, it must be possible to differentiate one concrete from another one which is subsumed under the same concept: see measurement omission.
A concept is just such a classification: a mental "integration" of at least two existents that share a common attribute or set of attributes (perhaps in different measures or degrees), each of which is for this purpose regarded as a unit of the concept. Once a concept is formed, it is given a specific definition and assigned a word; thereafter, it can be treated almost as a perceptual object, containing (or otherwise linking to) a wealth of implicit knowledge that need not be held explicitly in consciousness.
These concepts are formed by means of "measurement omission". Concepts are formed by isolating specific attributes of two or more similar concretes(such as tables, to use Rand's example), and omitting the particular measurements involved. The concept of table, therefore, is formed by isolating the attributes(Rand's "Conceptual Common Denominators") that constitute "table-ness"----ie, support(s) and a flat surface upon which items may be placed----and omitting the specific measurements involved; height, weight, color, number of supports, diameter of surface, etc. Once a concept is formed, it is defined by identifying its "essential" characteristic(s); that is, the characteristic or characteristics on which, within the context in which the concept is being formed, the most other characteristics depend.
The reference to "context" here is crucial. Since every concept is formed in a specific context, every definition is therefore contextual. If concepts are properly formed, then even though additional knowledge may require changes to one's definitions, one's later definitions will not contradict one's earlier ones.
What is the role of reason in this process? Reason consists in forming concepts through the use of logic, what Objectivism defines as "the art of noncontradictory identification".
Objectivism denies that the proposition is the fundamental unit of knowledge, arguing instead that concepts themselves constitute the building blocks of knowledge. So, in their way, do percepts, which consist of the knowledge that something exists. Concepts, however, consist of knowledge of what exists.
Concepts of (perceptual) entities (nouns, pronouns)
Concepts of perceptual entities are the first type of concepts we integrate.
Concepts of attributes or characteristics (adjectives)
Before we can develop concepts of attributes or characteristics (of entities) we must first have concepts of entities with which to work.
Concepts of motion (verbs)
Before we can develop concepts of motion (of an entity) we must first have concepts of entities with which to work.
Concepts of characteristics of motion (adverbs)
The concepts of characteristics of motion permit more distinguish between two or more instances of similar motions.
Concepts of materials
Concepts of materials are formed by observing differences in the constituent materials of entities.
Concepts of colors
Concepts of colors are a subdivision within concepts of attributes or characteristics.
Concepts of relationships (prepositions)
Concepts of relationships describe spatial or temporal relationships among existents.
Concepts of consciousness
Concepts of consciousness deal with the various actions of consciousness abstracting the action from the content which the action pertains to.
Concepts of relationships among thoughts (conjunctions)
These concepts are a subdivision within concepts of consciousness.
Concepts pertaining to the products of psychological processes
Concepts of method
Concepts of method are formed by retaining the distinguishing characteristics of the purposive course of action and of its goal, while omitting the particular measurements of both.
The fundamental concept of method, upon which all other concepts of method depend, is logic.
Concepts of measurement
A concept of measurement is a subdivision within concepts of method.
|Senses | Consciousness | Volition | Concepts: Unit, Concept-Formation|
|Objectivity | Knowledge: Context, Hierarchy | Reason: Certainty, Truth, the Arbitrary | Emotions|