The cultivation of the faculty of Abstraction depends very materially, in the first place, upon the exercise of Attention and Perception. Mill holds that Abstraction is primarily a result of Attention. Others hold that it is merely the mental process by which the attention is directed exclusively to the consideration of one of several qualities, properties, attributes, parts, etc. Hamilton says: "Attention and Abstraction then are only the same process viewed in different relations. They are, as it were, the positive and negative poles of the same act." The cultivation of Attention is really a part of the process of the cultivation of the faculty of Abstraction. Unless the Attention be directed toward the object and its qualities we will be unable to perceive, set aside, and separately consider the abstract quality contained within it. In this process, as indeed in all other mental processes, Attention is a prerequisite. Therefore, here, as in many other places, we say to you: "Begin by cultivating Attention."
Moreover, the cultivation of the faculty of Abstraction depends materially upon the cultivation of Perception. Not only must we sense the existence of the various qualities in an object, but we must also perceive them in consciousness, just as we perceive the object itself. In fact, the perception of the object is merely a perception of its various qualities, attributes and properties, for the object itself is merely a composite of these abstract things, at least so far as its perception in consciousness is concerned. Try to think of a horse, without considering its qualities, attributes and properties, and the result is merely an abstract horse—something which belongs to the realm of unreality. Try to think of a rose without considering its color, odor, shape, size, response to touch, etc., and you have simply an ideal rose which when analyzed is seen to be a nothing. Take away the qualities, properties and attributes of anything, and you have left merely a name, or else a transcendental, idealistic, something apart from our world of sense knowledge. Thus it follows that in order to know the qualities of a thing in order to classify it, or to form a general idea of it, we must use the Perception in order to interpret or translate the sense-impressions we have received regarding them. Consequently the greater our power of Perception the greater must be the possibility of our power of Abstraction.
Beyond the cultivation, use and exercise of the Attention and the Perception, there are but few practical methods for cultivating the faculty of Abstraction. Of course, exercise of the faculty will develop it; and the furnishing of material for its activities will give it the "nourishment" of which we have spoken elsewhere. Practice in distinguishing the various qualities, attributes and properties of objects will give a valuable training to the faculty.
Let the student take any object and endeavor to analyze it into its abstract qualities, etc. Let him try to discover qualities hidden from first sight. Let him make a list of these qualities, and write them down; then try to add to the list. Two or more students engaging in a friendly rivalry will stimulate the efforts of each other. In children the exercise may be treated as a game. Analysis of objects into their component qualities, attributes and qualities—the effort to extract as many adjectives applicable to the object—this is the first step. The second step consists in transforming these adjectives into their corresponding nouns. As for instance, in a rose we perceive the qualities which we call "redness," "fragrance," etc. We speak of the rose as being "red" or "fragrant"—then we think of "redness," or "fragrance" as abstract qualities, or things, which we express as nouns. Exercise and practice along these lines will tend to cultivate the faculty of Abstraction. By knowing qualities, we know the things possessing them.
CHAPTER IX.
ASSOCIATION OF IDEAS
Having formed general ideas, or Concepts, it is important that we associate them with other general ideas. In order to fully understand a general idea we must know its associations and relations. The greater the known associations or relations of an idea, the greater is our degree of understanding of that idea. If we simply know many thousands of separated general ideas, without also knowing their associations and relations, we are in almost as difficult a position as if we merely knew thousands of individual percepts without being able to classify them in general concepts. It is necessary to develop the faculty of associating ideas into groups, according to their relations, just as we group particular ideas in classes. The difference, however, is that these group-ideas do not form classes of a genus, but depend solely upon associations of several kinds, as we shall see in a moment.
Halleck says: "All ideas have certain definite associations with other ideas, and they come up in groups. There is always an association between our ideas, although there are cases when we cannot trace it.... Even when we find no association between our ideas, we may be sure that it exists.... An idea, then, never appears in consciousness unless there is a definite reason why this idea should appear in preference to others." Brooks says: "One idea or feeling in the mind calls up some other idea or feeling with which it is in some way related. Our ideas seem, as it were, to be tied together by the invisible thread of association, so that as one comes out of unconsciousness, it draws another with it. Thoughts seem to exist somewhat in clusters like the grapes of a bunch, so that in bringing out one, we bring the entire cluster with it. The law of association is thus the tie, the thread, the golden link by which our thoughts are united in an act of reproduction."
The majority of writers confine their consideration of Association of Ideas to its relation to Memory. It is true that the Laws of Association play an important part in Memory Culture, but Association of Ideas also form an important part of the general subject of Thought-Culture, and especially in the phase of the latter devoted to the development of the Understanding. The best authorities agree upon this idea and state it positively. Ribot says: "The most fundamental law which regulates psychological phenomena is the Law of Association. In its comprehensive character it is comparable to the law of attraction in the physical world." Mill says: "That which the law of gravitation is to astronomy, that which the elementary properties of the tissues are to physiology, the Law of Association of Ideas is to psychology."