Association of ideas

[1] In Thomas Hobbes's psychology much importance is assigned to what he called, variously, the succession, sequence, series, consequence, coherence, train of imaginations or thoughts in mental discourse.

John Locke had, meanwhile, introduced the phrase "association of ideas" as the title of a supplementary chapter incorporated with the fourth edition of his Essay, though with little or no suggestion of its general psychological import.

Dugald Stewart suggested resemblance, contrariety, and vicinity in time and place, though he added, as another obvious principle, accidental coincidence in the sounds of words, and further noted three other cases of relation: cause and effect, means and end, and premise and conclusion, as connecting trains of thought under circumstances of special attention.

The whole emotional side of mind ("the passions") he similarly resolved into an expectation of consequences based on past experience of pleasures and pains of sense.

But Hume was original also, when he spoke of it as a "kind of attraction which in the mental world will be found to have as extraordinary effects as in the natural, and to show itself in as many and as various forms."

A physician by profession, he sought to combine with an elaborate theory of mental association a minutely detailed hypothesis as to the corresponding action of the nervous system, based upon the suggestion of a vibratory motion within the nerves thrown out by Isaac Newton in the last paragraph of the Principia.

So far, however, from promoting the acceptance of the psychological theory, this physical hypothesis proved to have rather the opposite effect, and it began to be dropped by Hartley's followers (as Joseph Priestley, in his abridged edition of the Observations, 1775) before it was seriously impugned from without.

When it is studied in the original, and not taken upon the report of hostile critics, who would not, or could not understand it, no little importance must still be accorded to the first attempt, not seldom a curiously felicitous one, to carry through that parallelism of the physical and psychical, which since then has come to count for more and more in the science of mind.

Of this the point lay in no mere restatement, with new precision, of a principle of coherence among "ideas" (which were also called by Hartley "vestiges", "types" and "images"), but in its being taken as a clue by which to follow the progressive development of the mind's powers.

Holding that mental states could be scientifically understood only as they were analysed, Hartley sought for a principle of synthesis to explain the complexity exhibited not only in trains of representative images, but alike in the most involved combinations of reasonings and (as Berkeley had seen) in the apparently simple phenomena of objective perception, as well as in the varied play of the emotions, or, again, in the manifold conscious adjustments of the motor system.

So far from being content, like Hobbes, to make a rough generalization to all mind from the phenomena of developed memory, as if these might be straightway assumed, Hartley made a point of referring them, in a subordinate place of their own, to his universal principle of mental synthesis.

He expressly put forward the law of association, endued with such scope, as supplying what was wanting to Locke's doctrine in its more strictly psychological aspect, and thus marks by his work a distinct advance on the line of development of the experiential philosophy.

According to him, all that could be assumed was a general constitutional tendency of the mind to exist successively in states that have certain relations to each other, of itself only, and without any external cause or any influence previous to that operating at the moment of the suggestion.

Brown's chief contribution to the general doctrine of mental association, besides what he did for the theory of perception, was, perhaps, his analysis of voluntary reminiscence and constructive imagination, faculties that appear at first sight to lie altogether beyond the explanatory range of the principle.

In James Mill's Analysis of the Phenomena of the Human Mind (1829), the principle, much as Hartley had conceived it, was carried out, with characteristic consequence, over the psychological field.

With a much enlarged and more varied conception of association, Alexander Bain reexecuted the general psychological task, while Herbert Spencer revised the doctrine from the new point of view of the evolution hypothesis.

John Stuart Mill made only occasional excursions into the region of psychology proper, but sought, in his System of Logic (1843), to determine the conditions of objective truth from the point of view of the associationist theory, and, thus or otherwise being drawn into general philosophical discussion, spread wider than any one before him its repute.

To account for the fact of synthesis in cognition, in express opposition to associationism, as represented by Hume, was, in truth, his prime object, starting, as he did, from the assumption that there was in knowledge that which no mere association of experiences could explain.

As peculiar and widely different from anything conceived by the associationists as Herbart's metaphysical opinions were, he was at one with them and at variance with Kant in assigning fundamental importance to the psychological investigation of the development of consciousness.

In Friedrich Eduard Beneke's psychology also and in more recent inquiries conducted mainly by physiologists, mental association has been understood in its wider scope, as a general principle of explanation.

[2] In the later part of the 19th century the associationist theory was subjected to searching criticism, and it was maintained by many writers that the laws are both unsatisfactorily expressed and insufficient to explain the facts.

According to this doctrine, mental activity is ultimately reducible to particular feelings, impressions, ideas, which are disparate and unconnected, until chance association brings them together.

[7] F. H. Bradley's discussion deals with the subject purely from the metaphysical side, and the total result practically is that association occurs only between universals.

Secondly, it is quite false to regard an association as merely an aggregate of disparate units; in fact, the form of the new idea is quite as important as the elements which it comprises.

[7] The experimental methods in vogue in the early part of the 20th century to a large extent removed the discussion of the whole subject of association of ideas, depending in the case of the older writers on introspection, into a new sphere.