It is evident from the foregoing discussion that we may include under the term thinking all sorts of mental processes by which relations are apprehended between different objects of thought. Thus young children think as soon as they begin to understand something of the meaning of the objects of their environment. Even animals think by means of simple and direct associations. Thinking may therefore go on in terms of the simplest and most immediate, or the most complex and distant relationships.
Sensations and Percepts as Elements in Thinking.—Relations seen between sensations would mean something, but not much; relations seen between objects immediately present to the senses would mean much more; but our thinking must go far beyond the present, and likewise far beyond individual objects. It must be able to annihilate both time and space, and to deal with millions of individuals together in one group or class. Only in this way can our thinking go beyond that of the lower animals; for a wise rat, even, may come to see the relation between a trap and danger, or a horse the relation between pulling with his teeth at the piece of string on the gate latch, and securing his liberty.
But it takes the farther-reaching mind of man to invent the trap and the latch. Perception alone does not go far enough. It is limited to immediately present objects and their most obvious relations. The perceptual image is likewise subject to similar limitations. While it enables us to dispense with the immediate presence of the object, yet it deals with separate individuals; and the world is too full of individual objects for us to deal with them separately. It is in conception, judgment, and reasoning that true thinking takes place. Our next purpose will therefore be to study these somewhat more closely, and see how they combine in our thinking.
4. THE CONCEPT
Fortunately for our thinking, the great external world, with its millions upon millions of individual objects, is so ordered that these objects can be grouped into comparatively few great classes; and for many purposes we can deal with the class as a whole instead of with the separate individuals of the class. Thus there are an infinite number of individual objects in the world which are composed of matter. Yet all these myriads of individuals may be classed under the two great heads of inanimate and animate. Taking one of these again: all animate forms may be classed as either plants or animals. And these classes may again be subdivided indefinitely. Animals include mammals, birds, reptiles, insects, mollusks, and many other classes besides, each class of which may be still further separated into its orders, families, genera, species, and individuals. This arrangement economizes our thinking by allowing us to think in large terms.
The Concepts Serve to Group and Classify.—But the somewhat complicated form of classification just described did not come to man ready-made. Someone had to see the relationship existing among the myriads of animals of a certain class, and group these together under the general term mammals. Likewise with birds, reptiles, insects, and all the rest. In order to accomplish this, many individuals of each class had to be observed, the qualities common to all members of the class discriminated from those not common, and the common qualities retained as the measure by which to test the admission of other individuals into this class. The process of classification is made possible by what the psychologist calls the concept. The concept enables us to think birds as well as bluebirds, robins, and wrens; it enables us to think men as well as Tom, Dick, and Harry. In other words, the concept lies at the bottom of all thinking which rises above the seeing of the simplest relations between immediately present objects.
Growth of a Concept.—We can perhaps best understand the nature of the concept if we watch its growth in the thinking of a child. Let us see how the child forms the concept dog, under which he is able finally to class the several hundred or the several thousand different dogs with which his thinking requires him to deal. The child's first acquaintance with a dog is, let us suppose, with a pet poodle, white in color, and named Gyp. At this stage in the child's experience, dog and Gyp are entirely synonymous, including Gyp's color, size, and all other qualities which the child has discovered. But now let him see another pet poodle which is like Gyp except that it is black in color. Here comes the first cleavage between Gyp and dog as synonyms: dog no longer means white, but may mean black. Next let the child see a brown spaniel. Not only will white and black now no longer answer to dog, but the roly-poly poodle form also has been lost; for the spaniel is more slender. Let the child go on from this until he has seen many different dogs of all varieties: poodles, bulldogs, setters, shepherds, cockers, and a host of others. What has happened to his dog, which at the beginning meant the one particular little individual with which he played?
Dog is no longer white or black or brown or gray: color is not an essential quality, so it has dropped out; size is no longer essential except within very broad limits; shagginess or smoothness of coat is a very inconstant quality, so this is dropped; form varies so much from the fat pug to the slender hound that it is discarded, except within broad limits; good nature, playfulness, friendliness, and a dozen other qualities are likewise found not to belong in common to all dogs, and so have had to go; and all that is left to his dog is four-footedness, and a certain general form, and a few other dog qualities of habit of life and disposition. As the term dog has been gaining in extent, that is, as more individuals have been observed and classed under it, it has correspondingly been losing in content, or it has been losing in the specific qualities which belong to it. Yet it must not be thought that the process is altogether one of elimination; for new qualities which are present in all the individuals of a class, but at first overlooked, are continually being discovered as experience grows, and built into the developing concept.
Definition of Concept.—A concept, then, is our general idea or notion of a class of individual objects. Its function is to enable us to classify our knowledge, and thus deal with classes or universals in our thinking. Often the basis of a concept consists of an image, as when you get a hazy visual image of a mass of people when I suggest mankind to you. Yet the core, or the vital, functioning part of a concept is its meaning. Whether this meaning attaches to an image or a word or stands relatively or completely independent of either, does not so much matter; but our meanings must be right, else all our thinking is wrong.
Language and the Concept.—We think in words. None has failed to watch the flow of his thought as it is carried along by words like so many little boats moving along the mental stream, each with its freight of meaning. And no one has escaped the temporary balking of his thought by failure to find a suitable word to convey the intended meaning. What the grammarian calls the common nouns of our language are the words by which we name our concepts and are able to speak of them to others. We define a common noun as "the name of a class," and we define a concept as the meaning or idea we have of a class. It is easy to see that when we have named these class ideas we have our list of common nouns. The study of the language of a people may therefore reveal much of their type of thought.