Concepts (C )

Concepts are defined as abstract ideas. They are understood to be the fundamental building blocks of the concept behind principles, thoughts and beliefs.
They play an important role in all aspects of cognition. As such, concepts are studied by several disciplines, such as linguistics, psychology, and philosophy, and these disciplines are interested in the logical and psychological structure of concepts, and how they are put together to form thoughts and sentences. The study of concepts has served as an important flagship of an emerging interdisciplinary approach called cognitive science.

In contemporary philosophy, there are at least three prevailing ways to understand what a concept is:

* Concepts as mental representations, where concepts are entities that exist in the mind (mental objects)
* Concepts as abilities, where concepts are abilities peculiar to cognitive agents (mental states)
* Concepts as Fregean senses, where concepts are abstract objects, as opposed to mental objects and mental states

Concepts can be organized into a hierarchy, higher levels of which are termed "superordinate" and lower levels termed "subordinate". Additionally, there is the "basic" or "middle" level at which people will most readily categorize a concept. For example, a basic-level concept would be "chair", with its superordinate, "furniture", and its subordinate, "easy chair".

Concepts may be exact, or inexact.
When the mind makes a generalization such as the concept of ''tree'', it extracts similarities from numerous examples; the simplification enables higher-level thinking.
A concept is instantiated (reified) by all of its actual or potential instances, whether these are things in the real world or other ideas.

Concepts are studied as components of human cognition in the cognitive science disciplines of linguistics, psychology, and philosophy, where an ongoing debate asks whether all cognition must occur through concepts. Concepts are regularly formalized in mathematics, computer science, databases and artificial intelligence. Examples of specific high-level conceptual classes in these fields include classes, schema or categories. In informal use the word ''concept'' often just means any idea.

Ontology of concepts

A central question in the study of concepts is the question of what they ''are''. Philosophers construe this question as one about the ontology of concepts—what kind of things they are. The ontology of concepts determines the answer to other questions, such as how to integrate concepts into a wider theory of the mind, what functions are allowed or disallowed by a concept's ontology, etc. There are two main views of the ontology of concepts: (1) Concepts are abstract objects, and (2) concepts are mental representations.

Concepts as mental representations

The psychological view of concepts

Within the framework of the representational theory of mind, the structural position of concepts can be understood as follows: Concepts serve as the building blocks of what are called ''mental representations'' (colloquially understood as ''ideas in the mind''). Mental representations, in turn, are the building blocks of what are called '' propositional attitudes'' (colloquially understood as the stances or perspectives we take towards ideas, be it "believing", "doubting", "wondering", "accepting", etc.). And these propositional attitudes, in turn, are the building blocks of our understanding of thoughts that populate everyday life, as well as folk psychology. In this way, we have an analysis that ties our common everyday understanding of thoughts down to the scientific and philosophical understanding of concepts.

The physicalist view of concepts

In a physicalist theory of mind, a concept is a mental representation, which the brain uses to denote a class of things in the world. This is to say that it is literally, a symbol or group of symbols together made from the physical material of the brain. Concepts are mental representations that allow us to draw appropriate inferences about the type of entities we encounter in our everyday lives. Concepts do not encompass all mental representations, but are merely a subset of them. The use of concepts is necessary to cognitive processes such as categorization, memory, decision making, learning, and inference.

Concepts are thought to be stored in long term cortical memory, in contrast to episodic memory of the particular objects and events which they abstract, which are stored in hippocampus. Evidence for this separation comes from hippocampal damaged patients such as patient HM. The abstraction from the day's hippocampal events and objects into cortical concepts is often considered to be the computation underlying (some stages of) sleep and dreaming. Many people (beginning with Aristotle) report memories of dreams which appear to mix the day's events with analogous or related historical concepts and memories, and suggest that they were being sorted or organized into more abstract concepts. ("Sort" is itself another word for concept, and "sorting" thus means to organize into concepts.)

Concepts as abstract objects

The semantic view of concepts suggests that concepts are abstract objects. In this view, concepts are abstract objects of a category out of a human's mind rather than some mental representations.

There is debate as to the relationship between concepts and natural language. However, it is necessary at least to begin by understanding that the concept "dog" is philosophically distinct from the things in the world grouped by this concept—or the reference class or extension. Concepts that can be equated to a single word are called "lexical concepts".

The study of concepts and conceptual structure falls into the disciplines of linguistics, philosophy, psychology, and cognitive science.

In the simplest terms, a concept is a name or label that regards or treats an abstraction as if it had concrete or material existence, such as a person, a place, or a thing. It may represent a natural object that exists in the real world like a tree, an animal, a stone, etc. It may also name an artificial (man-made) object like a chair, computer, house, etc. Abstract ideas and knowledge domains such as freedom, equality, science, happiness, etc., are also symbolized by concepts. It is important to realize that a concept is merely a symbol, a representation of the abstraction. The word is not to be mistaken for the thing. For example, the word "moon" (a concept) is not the large, bright, shape-changing object up in the sky, but only ''represents'' that celestial object. Concepts are created (named) to describe, explain and capture reality as it is known and understood.

''A priori'' concepts

Kant maintained the view that human minds possess pure or '' a priori'' concepts. Instead of being abstracted from individual perceptions, like empirical concepts, they originate in the mind itself. He called these concepts