ASSOCIATION OF IDEAS, a phrase current in philosophy and psychology since the days of John Locke. The term aassociation" has had, in this connection, many different meanings. In popular psychology, it indicates the way the mind passes from idea to idea; or the way one idea suggests or ((reproduces) another. Thus, in passilig from the thought of gold to the recollection' of a recent visit to a mining camp and then to the plot of a novel laid in a mountainous region, one may be said to the story with the idea of the mining camp, and this, in turn, with the idea of gold (see MEMORY). It is but a step from this popular conception of association — asso ciation as to the notion that association is an explanation of reproduction. Association then becomes (to change the figure) not the actual passage from idea to idea, but the intangible bond which holds ideas together and which enables one idea (that is, the "gold° idea) to drag after it another (the 'learnt," idea). This second interpretation of the term is in disrepute among psychologists because no evidence of such a bond as the interpretation implies is to be found in consciousness. It may be urged, however, that even if association in this causal sense be undiscoverable by intro spection it may, nevertheless, be regarded as a general principle of mental activity;— as the means by which the mind creates knowledge. When, however, association is thus interpreted to mean a principle underlying and condition Mg the process of knowing it passes from psychology to epistemology (see PSYCHOLOGY). The doctrine of Associationism, which is con nected with the names of David Hume, James Mill Alexander Bain and other °association ists,i rests upon this epistemological meaning of the term.
Returning to the psychological use of the word ((association," we may note that the popu lar conception stands in need of modification and precision. (1) To say that mind ciates( idea with idea implies that ideas are by nature separate and distinct and require some (gentle (as Hume puts it) to bring them together. This is not true. Ideas are inter woven; they are organically connected; they are not held together as in a bundle. (2) In the second place, the popular use of the term is too narrow ; a chain of actions,. or of emotions, or of feelings, may be associated as well as a chain of ideas. In habitual performances, for example,— such as dressing—one act calls forth the next, this in turn the next, and so on; or emotion may be linked with emotion, as anger following fear; or, finally, associations may set out from a perception, as the thought of home from the sight of a letter. (3) Again, association does not necessarily imply a se quence of associated elements. It may be simultaneous, as well as successive; for ex ample, I see the table before me and at the same time, I apprehend it as a hard resisting substance, or I hear the rumble of a carriage behind me and I see, in my °mind's eye," its form and color (see PERCEMON). (4) Finally, association in the popular sense simply states that idea follows idea; it tells us nothing of the nature of the associated consciousness; of how, that is, an association differs from a per ception. Now association, in its strict tech nical sense, means the associated elements of consciousness; to illustrate, it means the mass of constantly shifting processes which make up mind while one is thinking gold— mining camp— novel. Just as there exist typical groups of mental processes which underlie the perception of a landscape, a swinging pendulum or a musical composition, there exist other typical groups — such as those already men tioned — which are known as associations.
Psychological work upon association has been directed, for the most part, upon the con ditions under which associative groups arise. These conditions have, since the days of Aris totle, been set down under the heading of or "laws' of association. Thus a is said to call up or reproduce b when a and b have, at some previous time, stood together in consciousness (law of contiguity), or when a has been the cause of b (law of causality), or when a resembles b (law of similarity), etc. At the present time, these ((laws" of association are usually reduced to two; the law of con tiguity and the law of similarity. But even these are by no means final or adequate state ments of the conditions under which associa tions arise; for — to point to only two or three of their imperfections— °similarity" is an ex tremely ambiguous term; it may mean simple likeness, or partial identity, or likeness of re lationship; and "contiguity' is indefinite—it does not determine how near processes must lie in consciousness in order for one to reproduce the other. Moreover, it should be said that there are thousands of contiguity and similarity connections that are never realized in associa tion; this follows from the fact that almost everything is, to some extent, similar to every thing else, and that the elementary processes of mind have appeared in almost every conceivable form of combination. Both terms are, then, too broad to have much signifi cance.. If we set them down as "laws,' we have still to determine under what particular conditions a given association is formed. Many of these particular and more important condi tions have been determined; they include re cency, frequency, vividness (the more recently or frequently or vividly a process or group of processes has stood in consciousness the greater the liability of its appearing in an associative connection), the general interests of the indi vidual mind (for example, botanical ideas crop up in the botanist's mind, geological ideas in the mind of the geologist) the presence or ab sence of inhibitory associations (if a has already stood associated with b and c its chances for associating with d will be lessened), mood (unpleasant subjects crowd into mind when one is depressed), etc. The actual liability of a given association being formed is thus seen to rest upon a great number of possible conditions. So far as there is any truth in a general all inclusive "law" of association it is best ex pressed as a law of neutral habit. This law is formulated by W. James as follows: "When two elementary brain-processes have been active together or in immediate succession, one of them, on reoccurring, tends to propagate its excitement into the other." The relation of this law to the law of contiguity is obvious.
Consult Claparede, 'T.:association des idees) (Paris 1903) ; Bain, A., and Moral Science' (London 1884) • Stout, 'A Manual of Psychology' (London 1899) • Jung, 'Lectures and Addresses at the Twentieth Anniversary of Clark University) (Worcester 1910) ; James, 'Principles of (New York 1890, ch. xiv) • Titchener, 'Experimental Psychology' (pt. II, 402 1901) . • Kuelpe, 'Outlines of Psy chology' (trans. 1895, 177ff); Calkins, 'Intro duction to Psychology' (1901, 157ff).