Concepts are the fundamental building blocks of our thoughts and beliefs . They play an important role in all aspects of cognition .  
Concepts arise as abstractions or generalizations from experience; from the result of a transformation of existing ideas; or from innate properties.  [ unreliable source? ] A concept is instantiated (reified) by all of its actual or potential instances, whether or not these things are in the real world or other ideas .
Concepts of cognition in the cognitive science of the disciplines of linguistics , psychology and philosophy . Concepts are used as formal tools or models in mathematics , computer science , databases and artificial intelligence where they are sometimes called classes , schema or categories . In informal use the word concept Often just means clustering Any idea .
In metaphysics , and especially ontology , a concept is a fundamental category of existence . In contemporary philosophy , there are at least three prevailing ways to understand a concept is:  [ See talk page ]
- 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 have Fregean senses (see sense and reference ), 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 definitely categorize a concept.  For example, a basic-level concept would be “chair”, with its superordinate, “furniture”, and its subordinate, “easy chair”.
Concepts in the representational theory of mind
Within the framework of the representational theory of mind , the structural position of concepts can be understood as: 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), be it “believing”, “doubting”, “wondering”, “accepting”, etc.). And these propositional attitudes, in turn, are the building blocks of our understanding of everyday life, folk psychology. In this way, we have an analysis of our common everyday understanding of the philosophical understanding of concepts. 
Nature of concepts
A central question in the study of concepts is the question of what concepts are . Philosophers constrain this question to the ontology of concepts – what they are really like. The ontology of the concepts of the answers to other questions, such as how to integrate concepts into a general 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. 
Platonist views of the mind constructs concepts as abstract objects, 
There is a debate between the concepts and the natural language .  However, it is necessary to understand that the concept of “dog” is philosophically distinct from the world in this world – or the reference class or extension . Concepts that can be equated to a single word are called “lexical concepts”. 
Study of concepts and conceptual structure in the disciplines of linguistics , philosophy , psychology , and cognitive science . 
In the simplest terms, a concept is a name or label that looks 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 be an artificial (man-made) object like a chair, computer, house, etc. Abstract concepts and knowledge such as freedom, equality, science, happiness, etc., are also symbolized by concepts. It is important to realize that a concept is a symbol, a representation of abstraction. The word is not mistaken for the thing. For example, the word “moon” is a large, bright, shape-changing object, but only representsthat celestial object. Concepts are created (named) to describe, explain and capture reality as it is known and understood.
A priori concepts
Kant declared that human minds possess pure gold a priori concepts. Instead of being abstracted from individual perceptions, like empirical concepts, they originate in the mind itself. He called these concepts categories , in the sense of the word that means predicate , attribute, characteristic, or quality . But these pure categories are predicates of things in general , not of a particular thing. According to Kant, there are 12 categories that constitute the understanding of phenomenal objects. Each category is that one predicate which is common to multiple empirical concepts. In order to explain how a prioriconcept can be related to individual phenomena, in a similar manner to a posteriori concept, Kant employed the technical concept of the schema . He held the account of the concept as an abstraction of experience is only partly correct. He called those concepts that result from abstraction “a posteriori concepts” (meaning concepts that arise out of experience). An empirical or a posteriori concept is a general representation ( Vorstellung ) or non-specific thought of which is common to several specific objects ( Logic , I, 1., §1, Note 1)
A concept is a common feature or characteristic. Kant investigated the way that empirical a posteriori concepts are created.
The logical acts of the understanding by which concepts are generated as follows:
- comparison , ie, the likening of mental images to one another in relation to the unity of consciousness;
- reflection , ie, the going back over different mental images, how they can be understood in one consciousness; and finally
- abstraction or the segregation of everything else by which the mental images differ …
In order to make our mental images into concepts, one must be able to compare, reflect, and abstract, for these three logical operations. For example, I see a fir, a willow, and a linden. In firstly comparing these objects, I notice that they are different from one another in respect of trunk, branches, leaves, and the like; further, however, I reflect only on what they have in common, the trunk, the branches, the leaves themselves, and their size, shape, and so forth; thus I gain a concept of a tree.- Logic, §6
In cognitive linguistics , abstract concepts are transformations of concrete concepts derived from embodied experience. The mechanism of transformation is structural mapping, in which they are selectively located on a blended space (Fauconnier & Turner, 1995, see conceptual blending ). A common class of blends are metaphors . This theory contrasts with the rationalist view that concepts are perceptions (or recollections , in Plato’s term) of an independently existing world of ideas, in which it denies the existence of any such realm. It also contrasts with the empiricist that the concepts are abstract generalizations of individual experiences, because the contingent and bodily experience is preserved in a concept, and not abstracted away. While the perspective is compatible with Jamesian pragmatism, the concept of the transformation of embodied concepts through structural mapping makes a distinct contribution to the problem of concept formation. [ quote needed ]
Plato was the starkest proponent of the realist thesis of universal concepts. By his view, concepts (and ideas in general) are innate ideas that have been instantiations of a transcendental world of pure forms that lay behind the veil of the physical world. In this way, universals have been explained as transcendent objects. Needless to say this form of realism with Plato’s ontological projects. This remark on Plato is not merely of a moral interest. For example, the view that numbers are platonic objects was revived by Kurt Gödel as a result of certain puzzles that he took to arise from the phenomenological accounts. 
Gottlob Frege , founder of the analytic tradition in philosophy, famously argued for the analysis of language in terms of sense and reference. For him, the sense of an expression in language describes a certain state of affairs in the world, namely, the way that some object is presented. Since many commentators view the notion of sense of the same notion of concept and the concept of the concept of the world, it seems that the world can not understand the world . Accordingly, concepts (as senses) have an ontological status (Morgolis: 7).
According to Carl Benjamin Boyer , in the introduction to the History of the Calculus and its Conceptual Development , concepts in calculus do not refer to perceptions. As long as the concepts are useful and mutually compatible, they are accepted on their own. For example, the concepts of the derivative and the integral are not considered to be of spatial or temporal perceptions of the external world of experience. Neither are they related to any way to mysterious limitsin which quantities are on the verge of nascence or evanescence, which is, coming into or going out of existence. The abstract concepts are now considered autonomous, even though they originated from the process of abstracting or taking away qualities from the past.
In a physicalist theory of mind , a concept is a mental representation, which the brain uses a class of things in the world. This is to say that it is literally, a symbol or group of symbols 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 lives.  Concepts of all-encompassing 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 . [ quote needed ]
Concepts are thought to be Stored in long-term cortical memory,  in contrast to episodic memory of the Particular objects and events qui They abstract, qui 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 to cortical concepts is often considered to be the underlying computation (some stages of) sleep and dreaming. Many people (beginning with Aristotle) report memories of dreams which appear to be mixed with analogous or related historical concepts and memories. (“Sort” is another word for concept, and “sorting” thus means to organize into concepts.)
Notable theories on the structure of concepts
The classical theory of concepts, aussi Referred to as the empiricist theory of concepts,  is the oldest theory about the structure of concepts (it can be traced back to Aristotle  ), and prominently Was Held up to the 1970s. The classical theory of concepts says that concepts have a definitional structure.  Adequate definitions of the kind required by this theory usually take the form of a list of features. These features are important to provide a comprehensive definition.  Features entailed by the definition of a concept must be Both Necessary and Sufficientfor membership in the class of things covered by a particular concept.  A feature is considered if every feature of the denoted class has that feature. A feature is considered sufficient.  For example, the classic example bachelor is Said to be defined by unmarried and man .  An entity is a bachelor (by this definition) if and only if it is both unmarried and a man. To check whether something is a member of the class, you compare its qualities to the features in the definition.  Another key part of this theory is that it obeys the law of the middle, which means that there are no partial members of a class, you are either in or out. 
The classical theory persisted for so long because it seemed intuitively correct and has great explanatory power. It can be explained how it would be used, how we use it to categorize and how we use the structure of a concept to determine its referent class.  In fact, for many years it was one of the major activities in philosophy – concept analysis .  Concept analysis is the act of trying to articulate the necessary and sufficient conditions for the membership of the class of a concept. [ citation needed ] For example, Shoemaker’s classic ” Time Without Change”but it is usually taken as a definition of time.
Arguments against the classical theory
Given That MOST later theories of concepts Were Born out of the rejection of Some or all of the classical theory,  It Seems Appropriate to give an account of what might be wrong with this theory. In the 20th century, philosophers such as Wittgenstein and Rosch argued against the classical theory. There are six primary arguments  summarized as follows:
- It seems that there are no definitions – especially those based on sensory primitive concepts. 
- It seems to be a case where our ignorance or error about the concept of a concept can not be defined. 
- Quine ‘s argument against analyticity in Two Dogmas of Empiricism also holds an argument against definitions. 
- Some concepts have fuzzy membership. There are items for which it is vague whether or not they fall into a particular referent class. This is not possible in the classical theory as everything has equal and full membership. 
- Rosch found typicality effects qui can not Be Explained by the classical theory of concepts, theory thesis Sparked the prototype.  See below.
- Psychological experiments show no evidence for our concepts as strict definitions. 
Prototype theory came out of problems with the classical view of conceptual structure.  Prototype theory says that the concepts specify properties that a class tends to possess, rather than must possess.  Wittgenstein , Rosch, Mervis, Berlin , Anglin, and Posner are a few of the key proponents and creators of this theory.   Wittgenstein describes the relationship between members of a class as family resemblances . There are no other conditions necessary for membership, a dog can still have a dog with only three legacies. This view is particularly supported by psychological experimental evidence for prototypicality effects.  Participants willingly and consistently rate objects in categories like ‘vegetable’ or ‘furniture’ as more or less typical of that class.   It seems that our categories are fuzzy psychologically, and have this structure has explanatory power.  We can judge an item’s membership to the referent class of a concept by comparing it to the typical member – the most central member of the concept. If it is similar, it will be cognitively admitted as a member of the relevant class of entities. Rosch suggests that it is possible to have a full copy of the article.  According to Lech, Gunturkun, and Suchan explain that categorization involves many areas of the brain, some of these are; visual association areas, prefrontal cortex, basal ganglia, and temporal lobe.
Theory-theory is a reaction to the previous two theories and develops them further.  This theory postulates that categorization by concepts is something like scientific theorizing.  Concepts are not learned in isolation, but rather are learned as part of our experiences with the world around us.  In this sense, the concepts’ structure relates to their relationships to other concepts as mandated by a particular mental theory about the state of the world.  How is it supposed to be a little less clear than the previous two theories, but is still a prominent and notable theory. This is supposed to explain some of the issues of ignorance and error that come up in prototype and classical theories as they are structured as a result of this theory. a whale is like, combining with our theory of what a fish is).  When we learn that we are not a fish, we are recognizing that we have made the theory of fish. In this sense, the Theory-Theory of concepts is responding to some of the issues of prototype theory and classic theory. 
According to the theory of ideasthesia (or “sensing concepts”), the activation of a concept may be the main mechanism for the creation of phenomenal experiments. Therefore, understanding how the brain processes concepts may be central to solving the mystery of how conscious experiences (or qualia ) emerge within a physical system eg, the sourness of the taste of lemon.  This question is also known as the hard problem of consciousness .   Research on ideasthesia is a finding of synahesis, where it is noted that a synesthetic experience requires an activation of a concept of the inducer. Later research expanded these results into everyday perception. 
There is a lot of discussion on the most effective theory in concepts. Another theory is semantic pointers, which uses perceptual and motor representations and these representations are like symbols. 
The term “concept” is traced back to 1554-60 (Latin conceptum – “something conceived”),  but what is today termed “the classical theory of concepts” is the theory of Aristotle on the definition of terms. [ quote needed ]
- Class (philosophy)
- Concept and object
- Concept map
- Conceptual blending
- Conceptual framework
- Conceptual history
- Conceptual model
- Conversation theory
- Formal concept analysis
- Fuzzy concept
- Hypostatic abstraction
- Notion (philosophy)
- Object (philosophy)
- Schema (Kant)
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