Infantine noises are comparatively homogeneous; alike as being severallylong-drawn and nearly uniform from end to end, and as being constantly repeatedwith but little variation of quality. They are quite un-co-ordinated -- thereis no integration of them into compound sounds. They are inarticulate, orwithout those definite beginnings and endings and joinings characterizingwords. Progress shows itself first in the multiplication of the inarticulatesounds: the extreme vowels are added to the medium vowels, and the compoundto the simple. Presently the movements which form the simpler consonantsare achieved, and some of the sounds become sharply cut; but this definitenessis partial, for only initial consonants being used, the sounds end vaguely.
While an approach to distinctness thus results, there also results, by combinationof different consonants with the same vowels, an increase of heterogeneity;and along with the complete distinctness which terminal consonants give,arises a further great addition to the number of unlike sounds produced.
The more difficult consonants and the compound consonants, imperfectly articulatedat first, are by-and-by articulated with precision; and hence arises anothermultitude of different and definite words -- words that imply many kindsof vocal movements, severally performed with exactness, as well as perfectlyintegrated into complex groups. The subsequent advance to dissyllables andpolysyllables, and to involved combinations of words, shows the still higherdegree of integration and heterogeneity eventually reached by these organicmotions.
The acts of consciousness correlated with these nervo-muscular acts, ofcourse go through parallel phases; and the advance from childhood to maturityyields daily proof that the changes which, on their physical side are nervousprocesses, and on their mental side are processes of thought, become morevarious, more defined, more coherent. At first the intellectual functionsare much alike in kind -- recognitions and classifications of simple impressionsalone go on; but in course of time these functions become multiform. Reasoninggrows distinguishable, and eventually we have conscious induction and deduction;deliberate recollection and deliberate imagination are added to simple unguidedassociation of ides; more special modes of mental action, as those whichresult in mathematics, music, poetry, arise; and within each of these divisionsthe mental movements are ever being further differentiated. In definitenessit is the same. At first the infant makes its observations so inaccuratelythat it fails to distinguish individuals. The child errs continually in itsspelling, its grammar, its arithmetic. The youth forms incorrect judgmentson the affairs of life. Only with maturity comes that precise co-ordinationof data which is implied by a good adjustment of thoughts to things. Lastly,with the integration by which simple mental acts are combined into complexmental acts, we see the like. In the nursery you cannot obtain continuousattention -- there is inability to form a coherent series of impressions;and there is a parallel inability to unite many co-existent impressions,even of the same order: witness the way in which a child's remarks on a picture,show that it attends only to the individual objects represented, and neverto the picture as a whole. But advancing years bring the ability to understandan involved sentence, to follow long trains of reasoning, to hold in onemental grasp numerous concurrent circumstances. A like progressive integrationtakes place among the mental changes we distinguish as feelings; which ina child act singly, producing impulsiveness, but in an adult act more inconcert, producing a comparatively balanced conduct.
After these illustrations supplied by individual evolution, we may dealbriefly with those supplied by general evolution, which are analogous tothem. A creature of very low intelligence, when aware of some large objectin motion near it, makes a spasmodic movement, causing, it may be, a leapor a dart. The perceptions implied are relatively simple, homogeneous, andindefinite: the moving objects are not distinguished in their kinds as injuriousor otherwise, as advancing or receding. The actions of escape, too, are allof one kind, have no adjustments of direction, and may bring the creaturenearer the source of peril instead of further off. At a higher stage thedart or the leap is away from danger: the nervous changes are so far specializedthat there results distinction of direction; indicating a greater varietyamong them, a greater co-ordination or integration of them in each process,and a greater definiteness. In still higher animals, able to discriminatebetween enemies and not-enemies, as a bird which flies from a man but notfrom a cow, the acts of perception have severally become united into morecomplex wholes, since cognition of certain differential attributes is implied;they have also become more multiform, since each additional component impressionadds to the number of possible compounds; and they have, by consequence,become more specific in their correspondences with objects -- more definite.
