CHAPTER V

On the law of Association--Its history traced from Aristotle to Hartley.

There have been men in all ages, who have been impelled as by an

instinct to propose their own nature as a problem, and who devote their

attempts to its solution. The first step was to construct a table of

distinctions, which they seem to have formed on the principle of the

absence or presence of the Will. Our various sensations, perceptions,

and movements were classed as active or passive, or as media partaking

of both. A still finer distinction was soon established between the

voluntary and the spontaneous. In our perceptions we seem to ourselves

merely passive to an external power, whether as a mirror reflecting the

landscape, or as a blank canvass on which some unknown hand paints it.

For it is worthy of notice, that the latter, or the system of Idealism

may be traced to sources equally remote with the former, or Materialism;

and Berkeley can boast an ancestry at least as venerable as Gassendi

or Hobbes. These conjectures, however, concerning the mode in which our

perceptions originated, could not alter the natural difference of Things

and Thoughts. In the former, the cause appeared wholly external,

while in the latter, sometimes our will interfered as the producing or

determining cause, and sometimes our nature seemed to act by a mechanism

of its own, without any conscious effort of the will, or even against

it. Our inward experiences were thus arranged in three separate classes,

the passive sense, or what the School-men call the merely receptive

quality of the mind; the voluntary; and the spontaneous, which holds the

middle place between both. But it is not in human nature to meditate on

any mode of action, without inquiring after the law that governs it;

and in the explanation of the spontaneous movements of our being, the

metaphysician took the lead of the anatomist and natural philosopher. In

Egypt, Palestine, Greece, and India the analysis of the mind had reached

its noon and manhood, while experimental research was still in its dawn

and infancy. For many, very many centuries, it has been difficult to

advance a new truth, or even a new error, in the philosophy of the

intellect or morals. With regard, however, to the laws that direct the

spontaneous movements of thought and the principle of their intellectual

mechanism there exists, it has been asserted, an important exception

most honourable to the moderns, and in the merit of which our own

country claims the largest share. Sir James Mackintosh,--(who, amid the

variety of his talents and attainments, is not of less repute for the

depth and accuracy of his philosophical inquiries than for the

eloquence with which he is said to render their most difficult results

perspicuous, and the driest attractive,)--affirmed in the Lectures,

delivered by him in Lincoln’s Inn Hall, that the law of association as

established in the contemporaneity of the original impressions,

formed the basis of all true psychology; and that any ontological or

metaphysical science, not contained in such (that is, an empirical)

psychology, was but a web of abstractions and generalizations. Of this

prolific truth, of this great fundamental law, he declared Hobbes to

have been the original discoverer, while its full application to the

whole intellectual system we owed to Hartley; who stood in the same

relation to Hobbes as Newton to Kepler; the law of association being

that to the mind, which gravitation is to matter.

Of the former clause in this assertion, as it respects the comparative

merits of the ancient metaphysicians, including their commentators, the

School-men, and of the modern and British and French philosophers from

Hobbes to Hume, Hartley, and Condillac, this is not the place to speak.

So wide indeed is the chasm between Sir James Mackintosh’s philosophical

creed and mine, that so far from being able to join hands, we could

scarcely make our voices intelligible to each other: and to bridge it

over would require more time, skill, and power than I believe myself

to possess. But the latter clause involves for the greater part a mere

question of fact and history, and the accuracy of the statement is to be

tried by documents rather than reasoning.

First, then, I deny Hobbes’s claim in toto: for he had been anticipated

by Des Cartes, whose work De Methodo, preceded Hobbes’s De Natura

Humana, by more than a year. But what is of much more importance,

Hobbes builds nothing on the principle which he had announced. He does

not even announce it, as differing in any respect from the general laws

of material motion and impact: nor was it, indeed, possible for him so

to do, compatibly with his system, which was exclusively material and

mechanical. Far otherwise is it with Des Cartes; greatly as he too in

his after writings (and still more egregiously his followers De la

Forge, and others) obscured the truth by their attempts to explain it

on the theory of nervous fluids, and material configurations. But, in

his interesting work, De Methodo, Des Cartes relates the circumstance

which first led him to meditate on this subject, and which since then

has been often noticed and employed as an instance and illustration of

the law. A child who with its eyes bandaged had lost several of his

fingers by amputation, continued to complain for many days successively

of pains, now in this joint and now in that, of the very fingers which

had been cut off. Des Cartes was led by this incident to reflect on the

uncertainty with which we attribute any particular place to any inward

pain or uneasiness, and proceeded after long consideration to establish

it as a general law: that contemporaneous impressions, whether images

or sensations, recall each other mechanically. On this principle, as a

ground work, he built up the whole system of human language, as one

continued process of association. He showed in what sense not only

general terms, but generic images,--under the name of abstract

ideas,--actually existed, and in what consist their nature and power.

As one word may become the general exponent of many, so by association

a simple image may represent a whole class. But in truth Hobbes himself

makes no claims to any discovery, and introduces this law of

association, or (in his own language) discursion of mind, as an

admitted fact, in the solution alone of which, and this by causes

purely physiological, he arrogates any originality. His system is

briefly this; whenever the senses are impinged on by external objects,

whether by the rays of light reflected from them, or by effluxes of

their finer particles, there results a correspondent motion of the

innermost and subtlest organs. This motion constitutes a

representation, and there remains an impression of the same, or a

certain disposition to repeat the same motion. Whenever we feel several

objects at the same time, the impressions that are left, (or in the

language of Mr. Hume, the ideas,)[24] are linked together. Whenever

therefore any one of the movements, which constitute a complex

impression, is renewed through the senses, the others succeed

mechanically. It follows of necessity, therefore, that Hobbes, as well

as Hartley and all others who derive association from the connection

and interdependence of the supposed matter, the movements of which

constitute our thoughts, must have reduced all its forms to the one law

of Time. But even the merit of announcing this law with philosophic

precision cannot be fairly conceded to him. For the objects of any two

ideas need not have co-existed in the same sensation in order to become

mutually associable. The same result will follow when one only of the

two ideas has been represented by the senses, and the other by the

memory.

Long however before either Hobbes or Des Cartes the law of association

had been defined, and its important functions set forth by Ludovicus

Vives. Phantasia, it is to be noticed, is employed by Vives to express

the mental power of comprehension, or the active function of the mind;

and imaginatio for the receptivity (via receptiva) of impressions, or

for the passive perception. The power of combination he appropriates

to the former: “quae singula et simpliciter acceperat imaginatio, ea

conjungit et disjungait phantasia.” And the law by which the thoughts

are spontaneously presented follows thus: “quae simul sunt a phantasia

comprehensa, si alterutrum occurrat, solet secum alterum representare.”

To time therefore he subordinates all the other exciting causes

of association. The soul proceeds “a causa ad effectum, ab hoc ad

instrumentum, a parte ad totum;” thence to the place, from place to

person, and from this to whatever preceded or followed, all as being

parts of a total impression, each of which may recall the other. The

apparent springs “saltus vel transitus etiam longissimos,” he explains

by the same thought having been a component part of two or more total

impressions. Thus “ex Scipione venio in cogitationem potentiae Turcicae,

propter victorias ejus de Asia, in qua regnabat Antiochus.”

But from Vives I pass at once to the source of his doctrines, and (as

far as we can judge from the remains yet extant of Greek philosophy)

as to the first, so to the fullest and most perfect enunciation of the

associative principle, namely, to the writings of Aristotle; and of

these in particular to the treatises De Anima, and “De Memoria,” which

last belongs to the series of essays entitled in the old translations

Parva Naturalia. In as much as later writers have either deviated from,

or added to his doctrines, they appear to me to have introduced either

error or groundless supposition.

In the first place it is to be observed, that Aristotle’s positions on

this subject are unmixed with fiction. The wise Stagyrite speaks of no

successive particles propagating motion like billiard balls, as Hobbes;

nor of nervous or animal spirits, where inanimate and irrational solids

are thawed down, and distilled, or filtrated by ascension, into living

and intelligent fluids, that etch and re-etch engravings on the brain,

as the followers of Des Cartes, and the humoral pathologists in general;

nor of an oscillating ether which was to effect the same service for the

nerves of the brain considered as solid fibres, as the animal

spirits perform for them under the notion of hollow tubes, as Hartley

teaches--nor finally, (with yet more recent dreamers) of chemical

compositions by elective affinity, or of an electric light at once the

immediate object and the ultimate organ of inward vision, which rises

to the brain like an Aurora Borealis, and there, disporting in various

shapes,--as the balance of plus and minus, or negative and positive,

is destroyed or re-established,--images out both past and present.

Aristotle delivers a just theory without pretending to an hypothesis;

or in other words a comprehensive survey of the different facts, and

of their relations to each other without supposition, that is, a fact

placed under a number of facts, as their common support and explanation;

though in the majority of instances these hypotheses or suppositions

better deserve the name of upopoiaeseis, or suffictions. He uses indeed

the word kinaeseis, to express what we call representations or ideas,

but he carefully distinguishes them from material motion, designating

the latter always by annexing the words en topo, or kata topon. On the

contrary, in his treatise De Anima, he excludes place and motion from

all the operations of thought, whether representations or volitions, as

attributes utterly and absurdly heterogeneous.

The general law of association, or, more accurately, the common

condition under which all exciting causes act, and in which they may

be generalized, according to Aristotle is this. Ideas by having been

together acquire a power of recalling each other; or every partial

representation awakes the total representation of which it had been

a part. In the practical determination of this common principle to

particular recollections, he admits five agents or occasioning

causes: first, connection in time, whether simultaneous, preceding,

or successive; second, vicinity or connection in space; third,

interdependence or necessary connection, as cause and effect; fourth,

likeness; and fifth, contrast. As an additional solution of the

occasional seeming chasms in the continuity of reproduction he proves,

that movements or ideas possessing one or the other of these five

characters had passed through the mind as intermediate links,

sufficiently clear to recall other parts of the same total impressions

with which they had co-existed, though not vivid enough to excite that

degree of attention which is requisite for distinct recollection, or

as we may aptly express it, after consciousness. In association then

consists the whole mechanism of the reproduction of impressions, in the

Aristotelian Psychology. It is the universal law of the passive fancy

and mechanical memory; that which supplies to all other faculties their

objects, to all thought the elements of its materials.

In consulting the excellent commentary of St. Thomas Aquinas on the

Parva Naturalia of Aristotle, I was struck at once with its close

resemblance to Hume’s Essay on Association. The main thoughts were

the same in both, the order of the thoughts was the same, and even the

illustrations differed only by Hume’s occasional substitution of more

modern examples. I mentioned the circumstance to several of my literary

acquaintances, who admitted the closeness of the resemblance, and

that it seemed too great to be explained by mere coincidence; but

they thought it improbable that Hume should have held the pages of the

Angelic Doctor worth turning over. But some time after Mr. Payne showed

Sir James Mackintosh some odd volumes of St. Thomas Aquinas, partly

perhaps from having heard that he had in his Lectures passed a high

encomium on this canonized philosopher; but chiefly from the fact, that

the volumes had belonged to Mr. Hume, and had here and there marginal

marks and notes of reference in his own hand writing. Among these

volumes was that which contains the Parva Naturalia, in the old Latin

version, swathed and swaddled in the commentary afore mentioned

It remains then for me, first to state wherein Hartley differs from

Aristotle; then, to exhibit the grounds of my conviction, that

he differed only to err: and next as the result, to show, by what

influences of the choice and judgment the associative power becomes

either memory or fancy; and, in conclusion, to appropriate the remaining

offices of the mind to the reason, and the imagination. With my best

efforts to be as perspicuous as the nature of language will permit

on such a subject, I earnestly solicit the good wishes and friendly

patience of my readers, while I thus go “sounding on my dim and perilous

way.”