are simultaneously present to the senses, to the cases in which some of their elements are present to the senses and some not, we meet with a sensory co-ordination of a new and higher order. And where the responding motions, no longer°occurring as an inseparable group, are divided by intervals that vary according to circumstances, we see a parallel progress in motor co-ordination. A creature which when pursued runs to its burrow, supplies us with an instance ol the one; while an instance of the other occurs in any process which, like the building of a nest, is effected by instalments variously interrupted by other procedures. From the stage in which a single past impression unites with many present ones to compose a special stimulus, and in which the action completed at intervals is tolerably homogeneous in character, the advance is towards a union of many past impressions with present ones, and towards a kind of action increasingly heterogeneous in its instalments, as well as in the manner of their succession. In men's daily transactions, the complex sights, sounds, and muscular sensations, serving for immediate guidance, are co-ordinated with recollections of the persons, places, things, events, to which those transactions refer; and one who mistakes the hour at which certain business is to be done with certain people at a certain office, shows us how a failure arises from imperfect coordination of the past and present impressions constituting the directive stimulus. The operations by which wheat is sown, weeded, reaped, stacked, thrashed, winnowed, taken to market, and sold, compose a series of widely-different groups of actions (each consisting of many minor groups), divided by dissimilar and variable intervals, all combined to achieve a single end; and to achieve it they must be a3justed in a particular manner. The elaborateness of these advanced correspondences in which time past, time present, and time future are alike involved, and which have simultaneous reference to sundry places in space, is an THE CO-ORDINATION OF CORftESPONDENCES. 373 elaborateness measured by the number of past impressions compounded with present ones, and past actions coinpounded with present ones. But the all-essential thing is the definiteiiess with which the combination is adapted to the combination of external circumstances — the goodness of the co-ordination.
§ 168. A still higher species of co-ordination growing imperceptibly out of the last, and vaguely seen even m the illustrations just given, involves not simply the union of past with present specialities, but the union of generalities with both. The perception received yesterday when the barometer stood at " Fair/' together with the perception received to-day, when it stands at (C Change/5 bring no conclusion unless joined to the generalization that a fall of the mercurial column commonly indicates rain. Nay, before a true inference can be drawn for to-morrow's guidance, these data must be joined with the further generalization, that only when the air is charged with water to a certain degree is rain indicated by a falling barometer. In other cases, as in that of a physician prescribing for his patient, many remembered observations of bygone symptoms, many observations of existing ones, and many general truths serving to interpret the changes that have taken place, must enter into that directive process which terminates in an appropriate course of treatment.
But the most developed form of co-ordination is that exhibited by quantitative science. In this, not only must.ft" specialities be combined with generalities after a perfectly definite manner; but there must be perfect definiteness in each constituent of the combination. The perceptions by which the data are obtained must have their elements so exactly co-ordinated as to give measured results. The law's of dependsnce must be so known that they can be expressed numerically. And the process by which, out of data and laws, the prevision is finally evolved, must have each step united with preceding and succeeding steps in a mode that is quite specific. An estimate of the horse-power required to move a given steam-vessel at a specified speed, involves these general truths:— that the resistance encountered by a body moving through fluid varies as the square of the velocity; that the area opposed by a vessel to the water varies as the squares of its dimensions; that the tonnage varies as the cubes of the dimensions; with sundry others. Particular forces,, weights, specific gravities, lengths, breadths, depths, have to be combined with these o-eneral truths, each with each; and the results have to be farther combined after particular modes. If one of the generalities be applied to the wrong specialities — if the formula for resistance be brought to bear, not on the figures representing sectional area, but on those representing tonnage— if the data be inexact, or the principles be misunderstood, or the calculation be erroneously performed, that is — if there be imperfect co-ordination of the various mental acts involved; a false conclusion is reached: there is a failure of cognition: the internal relations are not rightly adjusted to external ones, as is proved by the result.
It will farther elucidate both this doctrine of co-ordination and the general doctrine of correspondence, if we consider how, for the perfect adjustment of inner to outer relations, there must exist in the first, elements and changes symbolizing all the essential elements and changes in the last. Undeveloped life is led by associations among some of the superficial attributes of things. Developed life is led by associations among those fundamental attributes on which the actions of the things depend. There is no invariable connexion between a loud sound and an adjacent enemy; and hence, creatures in which one of these serves as an index to the other, are often wrong in the adjustments of their internal relations to external ones. But the connexion between linear dimensions and solid contents, or between velocity and momentum,, is constant, and therefore - THE CO-ORDINATION OF CORBESPONDENCES. 375 affords infallible guidance. Before this infallible guidance can be had, however, all the elements of the relation must be known. Whenever a group of inner relations, or cognition, is completely conformed to a group of outer relations, or phenomenon, by a rational process — whenever there is what we call an understanding of the phenomenon — the composition of the phenomenon is, in a sense, paralleled by the composition of the cognition. The law that the momentum of a moving body varies as its velocity multiplied into its weight, cannot be known until there exist in the mind conceptions answering to momentum, velocity, and weight; it cannot be known until there exist in the mind ideas of time, space, and matter, without which velocity and momentum are inconceivable; it cannot be known until there are processes of thought answering to those quantitative connexions which " varies as " and " multiplied into " indicate -, nay, the law cannot be known until the states of consciousness symbolizing time and space, are so co-ordinated as to symbolize velocity; nor until the states of consciousness symbolizing velocity and weight are so co-ordinated as to symbolize momentum; nor until these three are again co-ordinated according to those laws of relation implied by "varies as" and "multiplied into."
That is, every attribute necessarily involved in the phenomenon must have its internal representative; and the several laws of dependence among these attributes must be each represented by some constant relation among their representatives.
These facts bring out into yet clearer light, the general doctrine variously presented in the preceding chapters. That in these highest manifestations of Life produced by the culture of civilization — these quantitative previsions which imply such intense vital action while they so greatly subserve self-preservation by facilitating commerce and the arts — there should be this elaborate and complete co-ordination of inner relations to symbolize outer relations, serves as a crowning illustration of the truths, that Life is tne maintenance of a correspondence between the organism and its environment, and that the degree of Life varies as the degree of correspondence. The many proofs which have been given that the life and the correspondence advance hand in hand,, become doubly conclusive on finding that the two culminate together- CHAPTER X.
THE INTEGRATION OF COIiRESPONDENCES.
§ 169. There is one more point of view from which tlie phenomena of Life must be contemplated. We have to note how,, out of co-ordination, there grows up integration. Compound impressions, as well as the compound motions guided by them,, continually approach in their apparent characters to simple impressions and simple motions. The co-ordinated elements of any stimulus or of any act ever tend towards union; and eventually become distinguishable from one another only by analysis. Further, the connexion between stimulus and act also becomes constantly closer; so that at last they seem two sides of the same change.
Only by virtue of this law do the higher kinds of correspondence become possible. In its absence, complex impressions could not generate complex actions with the needful rapidity; nor would there be time for that immense multiplicity of adjustments which developed life displays. If the two organic changes which constitute sensation and motion, did not, in superior creatures, follow with greater rapidity than the withdrawal of a snail into its shell follows the touch of its horn, all those correspondences with the environment which imply any quickness of adaptatiftn would be impracticable. If the period that elapses between the gaze of a young child at a stranger and the fit of crying that follows (a period during which the component visual impressions are being co-ordinated), were habitually paralleled in the perceptions of adults— if compound cognitions were not formed, and the appropriate operations produced by them,, in periods incomparably briefer,, human life would cease.
The necessity for this progressive integration will be most clearly understood if, regarding sensations as symbols and perception as the interpretation of groups of symbols,, we observe what takes place with verbal symbols and the meanings they convey. Where intelligence is but little evolved,, a single sensation,, as of scent, serves the organism for an index of the combined attributes with which such scent is connected • and similarly, in undeveloped language a simple sound is used to indicate a complex idea. In either case, this system answers very well within narrow limits. But a large increase in the number of correspondences requires another system. By scent, only some objects can be distinguished: many are scentless. Simple sounds and marks are too few in number to represent any considerable variety of ideas. Hence, in either case, compound symbols must be used before there can be a great multiplication of the correspondences. Things that are without odour, and things that are alike in odour, can be divided into sub-classes when impressions of colour and size, as well as of scent, can be appreciated. And when simple sounds are endlessly modified by articulations, and simple signs are replaced by composite signs, it becomes possible verbally to indicate an infinity of objects, acts, qualities, &c. But on what condition only does this more elaborate language become serviceable? or, to confine the attention to one division of it— What is required before composite written signs can supplant simple written signs?
It is required that the constituent elements of each composite sign shall be so efficiently co-ordinated, so rapidly united in the act of perception, so integrated, as to become practically one. Had the letters that make up every word THE INTEGRATION OE CORRESPONDENCES. 379 to "be separately identified, as tlie child identifies them when learning to read,, the system would be of little or no use. Able, though it might be, to express with precision all verbal articulations, it could never compete with the limited system of simple signs, did it remain thus cumbrous in its application. Similarly with the primordial language of perception. If the several colours, size, shape, motion, direction, and distance, of an object, had to be successively identified by the creature perceiving it — if the object had to be spelled out in this deliberate fashion; the method of recognition by combined sensations would yield in utility to the method of recognition by a single sensation. Universal in its powers, it would yet be too slow of use to satisfy the requirements. In both cases, however, the progressive integration of the component correspondences removes this difficulty, by practically reducing the compound signs to simple ones. A word made up of a dozen letters comes eventually to be recognized as quickly as a single letter. The host of impressions involved in the perception of a carriage, seemingly take no more time to receive and interpret than a single sound or taste. And.thus there is immeasurable gain in the speciality of the correspondences, without loss in their rapidity. Let us glance at the results.
§ 170. It is needless to dwell on the apparent simultaneity with which the many visual sensations given us by an object, arouse those ideas of tangible extension, of resistance, of texture, with which experience has joined them: the entire group of sensations and the inferences drawn from them, seeming to constitute but a single state of consciousness. Nor is it requisite to do more than indicate the exceeding precision with which the most complex assemblages • of these symbols are instantly distinguished from nearly identical assemblages; as shown in our ability to recognize by a single look, a particular person, and even his particular mental state. But to convey a vivid idea of the manner in which, this integration of correspondences subserves the perceptions, it will be well to describe an experiment showing its extreme strength and rapidity.
We judge of distance by at least three separate indications. When the observed object is known to us, the angle it subtends, or, rather, the space which its image covers on the retina, aids in the estimate. The particular focal adjustments which the eyes undergo to obtain distinct vision, and which are accompanied by certain muscular sensations, assist. And the muscular sensations accompanying due convergence of the visual axes, supply a third evidence. In ordinary vision these indications agree. But by that ingenious instrument of Professor Wheatstone's invention — the Pseudoscope — the last two are made to contradict each other.
The muscular actions by which the visual axes are adjusted being the more marked, and accompanied by the stronger sensations, give the preponderating evidence; and the result is that when looked at through the Pseudoscope, convex objects seem concave and concave objects seem convex. By particular management, however — that is, by adding to the evidence from focal adjustment some further evidence — the verdict of consciousness may be suddenly reversed. If, after contemplating the inside of a cup and wondering at its apparent convexity, the cup be turned laterally little by little, so that the outside gradually comes into view and the opening grows more elliptical, there presently arrives a time when the perception all at once changes, and the cup is seen under its ordinary aspect. Now the fact here to be remarked as so significant, is the impossibility of any intermediate or hesitating judgment. Notwithstanding the conflict of evidence, there is, save at the moment of change, a definite perception either of concavity or of convexity.
The perception is not incomplete or obscure, but perfectly distinct. The preponderating impressions dragging with them all those other impressions which they habitually T1TE INTEGRATION OF CORRESPONDENCES. 381 imply, produce the same effect as though, these other impressions were actually received, instead of the opposite ones being received. The co-ordinated sensations have become ao integrated that no considerable part of the group can be present to consciousness without the whole group being present.
With the executive processes as well as with the directive processes, this integration takes place. A long-employed combination of muscular actions is at last almost undecomposable. The tricks of walk, of attitude, of manual action, which children acquire, and of which it is so difficult to break them, furnish examples. We have another example in stammering, which, commencing as it often does with imitation, becomes, when once established, next to incurable. So, too, is it with peculiarities of handwriting. The motions of the fingers having by years of practice been coordinated in a particular manner, cannot be otherwise coordinated without a degree of labour to which few are equal. Though, by moving them slowly and with attention, the fingers may be made to produce differently- formed letters; yet, on the attention being relaxed and the usual speed resumed, the letters re-acquire their old characters. Similarly in all handicrafts, chains of perpetually-repeated muscular actions, however complex, eventually approximate in rapidity and ease to simple motions; and, at the same time, cease to be capable of modified adjustment — tend more and more to produce one another automatically — grow inseparable— become integrated.
Similar integrations go on between cognitions and the operations guided by them. In the child learning to walk, or to lay hold of a neighbouring object, or to pronounce a word, there is a deliberate and conscious modification of the motions in obedience to the sensations. But in after-yeafs the various muscular adjustments by which, from minute to minute, the intentions are fulfilled, follow the will instantaneously and without oversight of the intellect. While absorbed in gossip, the seamstress makes stitch, after stitch by a co-ordination of sensations and actions that has become next to instinctive. When deep in thought— " absent in mind/' as the phrase is — the occurrence of particular perceptions will often be unconsciously followed by the actions appropriate to them: sometimes with ludicrous effect. The start on one side caused by a loud noise close at hand, or the throwing out of the arms to regain the balance after having slipped, shows us how directive and executive processes, originally quite distinct, come to be so united that one follows the other not only instantly and without volition, but often without the possibility of prevention. Even where the impressions and motions are both extremely complex, the law may be traced; witness the feats of a skilful billiard-player. In one of his strokes we see the relative positions of the three balls to one another, to the cushions, and to the pockets, all united into a complex visual impression co-ordinated with the greatest nicety; we see the direction of the cue, its adjustment to the ball, the strength of its impact, and the quality of its impact, all accurately modified to suit the requirements; and we see that by long habit the compound impression has been so united with the compound action, that the one follows the other almost mechanically. Wo reasoning or calculation is required; or, indeed, is permissible. For it is notorious that in games of skill, any lengthened consideration or active interference on the part of the higher faculties, almost inevitably causes a failure. The direct guidance that has been established between the constituent sensations and constituent motions, must be allowed free play; and success becomes sure in proportion as, by constant co-ordination, the combined changes become practically one change.
* In all which we may perceive how that automatic character shown in the simple correspondences of inferior creatures, is gradually assumed by more complex correspondences— how that integration which the reflex and THE INTEGRATION OF CORRESPONDENCES, 383 purely instinctive correspondences perfectly exemplify, is partially exemplified by all higher correspondences.
§ 171. Not only to the constituents of immediate perception, to the elements of composite motion, and to the combination of the two, does this law apply; it applies also to the highest processes of cognition. The most advanced conceptions of science display it equally with the achievements of manipulatory skill. For making a generalization is,, in reality, integrating the va.rious separate cognitions which the generalization includes — uniting them into a single cognition. After there has been a mental accumulation of facts presenting a certain community of nature (remembered first as isolated facts and after further experience colligated as facts having some resemblance), there suddenly,, on the occurrence perhaps of some typical example, arises a cognition of the relation of co-existence or sequence common to the whole group: the particular factsr before loosely aggregated, all at once crystallize into a general fact — are integrated. The mode in which this result is brought about, is the same in these highest cases as in the lowest cases. Continuous repetition of experiences in which any two sensations are always joined, any two muscular contractions constantly performed together, or any perception uniformly followed by a special motion, results in the greater or less integration of the component changes; and, similarly, continuous repetition of those more complex experiences which, though superficially unlike, one and all present the same fundamental relation of co-existence or sequence, ultimately establishes a union in thought between the elements of" this relation, and still-multiplying experiences go on consolidating the union. It will be obvious without details, that the same thing holds respecting the generalization of generalizations. The integration of correspondences is traceable from the simplest np to the most elaborate of the intellectual processes. And in the 884 GENEBAL SYNTHESIS.
last, as in tlie first, tlie effect is to simplify tlie directive and executive actions, and so to make practicable those adjustments that would else fail from tlie too slow succession of the processes they involved. For as the perception of a complex object would commonly be useless if the percipient had to spell out the constituent sensations; so, any series of compound experiences which, embodied in a generalization, afford valuable guidance, would be of little or no service if every member of the series had to be separately recollected before the guiding cognition could be formed.
§ 172. This gradual union of the elements of any internal change by which the organism adapts its acts to an external co-existence or sequence, has been, in common with previous traits of advancing correspondence, abundantly displayed in the course of human evolution. Progress in integration has been a necessary accompaniment of progress in speciality and complexity, since without it highly special and complex correspondences cannot be achieved; and hence in proportion as civilization has displayed the last it must have displayed the first. The one having been illustrated in detail it is therefore needless to illustrate the other. Similarly, greater length and degree of Life, involved as they are by greater complexity and speciality of correspondence, have accompanied that greater integration which has rendered these possible.
CHAPTER XI.
CHAPTER XI.
THE CORRESPONDENCES IN THEIR TOTALITY.
§ 173. Thus then we find illustrated in all ways the truth enunciated at the outset, that the connexions among vital actions directly or indirectly correspond with the connexions among actions in the environment. That method by which we sought out the fundamental fact on which to base a Synthetic Psychology, is justified by its results. On comparing the phenomena of mental life with the most nearly allied phenomena — those of bodily life — and inquiring what is common to both groups, a generalization was disclosed which proves on examination to express the essential character of all mental actions. Regarded under every variety of aspect, intelligence is found to consist in the establishment of correspondences between relations in the organism andj?elations m the environment; and the entire; development of intelligence may be formulated" as the progress^pf such correspondences in Space, in Time, in Speciajit^n.^^^ As hinted more than once, these several modes in which the advance of the correspondence displays itself, are but so many different aspects of one mode. The vast array $f phenomena which, for convenience' sake, we_haye jGcmsiderecl under^d^tinct heads, form in reality one genera],, continuous, and inseparable eypluSon. By going onlimul -taneously, the various orders of progress described have c o rendered one another possible. Every kind of advance lias opened the way for advances of other kinds; and these again have reacted in like manner. All,„ have been furthered by each; and each has been furthered by all. Not only is extension of the correspondence in Time, at first rendered possible only by its extension in Space; but ultimately, as in the researches of astronomers, the greatest extension of the correspondence in Space is achieved through its extension in Time. Not only does progress of the correspondence in Time and Space involve increase in its speciality; but, eventually, that immense increase in speciality implied by the making of telescopes and chronometers, gives a new progress to the correspondence in Time and Space. On the one hand, such greater complexity of the correspondence as is shown by discriminating between objects which have many attributes in common, amounts to advance in its speciality; and, on the other hand, advance in speciality is that without which greater complexity of correspondence cannot be reached. While, by the correspondence to higher generalities, the way is opened for more complex and more special correspondences; it is by accumulated experiences of such more complex and more special correspondences that the correspondence to still higher generalities is made possible. At both