Concepts

   1) Concepts Promote Cognitive Economy

   From a psychological perspective, concepts are mental representations of classes (e.g., one's beliefs about the class of dogs or tables), and their most salient function is to promote cognitive economy. . . . By partitioning the world into classes, we decrease the amount of information we must perceive, learn, remember, communicate, and reason about. Thus, if we had no concepts, we would have to refer to each individual entity by its own name; every different table, for example, would be denoted by a different word. The mental lexicon required would be so enormous that communication as we know it might be impossible. Other mental functions might collapse under the sheer number of entities we would have to keep track of.

   Another important function of concepts is that they enable us to go beyond the information given. . . . When we come across an object, say a wolf, we have direct knowledge only of its appearance. It is essential that we go beyond appearances and bring to bear other knowledge that we have, such as our belief that wolves can bite and inflict severe injury. Concepts are our means of linking perceptual and nonperceptual information. We use a perceptual description of the creature in front of us to access the concept wolf and then use our nonperceptual beliefs to direct our behavior, that is, run. Concepts, then, are recognition devices; they serve as entry points into our knowledge stores and provide us with expectations that we can use to guide our actions.

   A third important function of concepts is that they can be combined to form complex concepts and thoughts. Stoves and burn are two simple concepts; Stoves can burn is a full-fledged thought. Presumably our understanding of this thought, and of complex concepts in general, is based on our understanding of the constituent concepts. (Smith, 1988, pp. 19-20)

   2) The Nature of Concepts

   The concept may be a butterfly. It may be a person he has known. It may be an animal, a city, a type of action, or a quality. Each concept calls for a name. These names are wanted for what may be a noun or a verb, an adjective or an adverb. Concepts of this type have been formed gradually over the years from childhood on. Each time a thing is seen or heard or experienced, the individual has a perception of it. A part of that perception comes from his own concomitant interpretation. Each successive perception forms and probably alters the permanent concept. And words are acquired gradually, also, and deposited somehow in the treasure-house of word memory. . . . Words are often acquired simultaneously with the concepts. . . . A little boy may first see a butterfly fluttering from flower to flower in a meadow. Later he sees them on the wing or in pictures, many times. On each occasion he adds to his conception of butterfly.

   It becomes a generalization from many particulars. He builds up a concept of a butterfly which he can remember and summon at will, although when he comes to manhood, perhaps, he can recollect none of the particular butterflies of past experience.

   The same is true of the sequence of sound that makes up a melody. He remembers it after he has forgotten each of the many times he heard or perhaps sang or played it. The same is true of colours. He acquires, quite quickly, the concept of lavender, although all the objects of which he saw the colour have faded beyond the frontier of voluntary recall. The same is true of the generalization he forms of an acquaintance. Later on he can summon his concept of the individual without recalling their many meetings. (Penfield, 1959, pp. 228-229)