Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/57

PSYCHOLOGY 45 untaught ability " what they slowly and painfully found out. But if we are to attempt to follow the genesis of mind from its earliest dawn it is the primary experience rather than the eventual instinct that we have first of all to keep in view. To this end, then, it is proposed to assume that we are dealing with one individual which has continuously advanced from the beginning of psychical life, and not with a series of individuals of which all save the first have inherited certain capacities from its pro- genitors. The life -history of such an imaginary indi- vidual, that is to say, would correspond with all that was new, all that could be called evolution or development, in a certain typical series of individuals each of whom advanced a certain stage in mental differentiation. On the other hand, from this history would be omitted that inherited reproduction of ancestral experience, or tendency to its reproduction, by which alone, under the actual con- ditions of existence, progress is possible. If an assumption of this kind had been explicitly avowed by the psychologists who have discussed the growth of experience in accordance with the evolution hypothesis, not a few of the difficulties in the way of that hypothesis might have been removed. That individual minds make some advance in the complexity and distinct- ness of their presentations between birth and maturity is an obvious fact ; heredity, though a less obvious fact, is also beyond question. Using Locke's analogy of a writing-tablet or let us say an etching-tablet by way of illustration, we may be sure that every individual started with some features of the picture completely pre- formed, however latent, others more or less clearly out- lined, and others again barely indicated, while of others there is as yet absolutely no trace. But the process of reproducing the old might differ as widely from that of producing the new as electro typing does from engraving. However, as psychologists we know nothing directly about it ; neither can we distinguish precisely at any link in the chain of life what is old and inherited original in the sense of Locke and Leibnitz from what is new or acquired original in the modern sense. But we are bound as a matter of method to suppose all complexity and differentia- tion among presentations to have been originated, i.e., experimentally acquired, at some time or other. So long, then, as we are concerned primarily with the progress of this differentiation we may disregard the fact that it has not actually been, as it were, the product of one hand dealing with one tabula rasa but of many hands, each of which, starting with a reproduction of what had been wrought on the preceding tabulae, put in more or fewer new touches before devising the whole to a successor who would proceed in like manner. re- What is implied in this process of differentiation or mental growth and what is it that grows or becomes n " differentiated 1 these are the questions to which we must now attend. Psychologists have usually represented mental advance as consisting fundamentally in the combination and recombination of various elementary units, the so-called sensations and primitive movements, or, in other words, in a species of " mental chemistry." If we are to resort to physical analogies at all a matter of very doubtful pro- priety we shall find in the growth of a seed or an embryo far better illustrations of the unfolding of the contents of consciousness than in the building up of molecules : the process seems much more a segmentation of what is origin- ally continuous than an aggregation of elements at first independent and distinct. Comparing higher minds or stages of mental development with lower by what means such comparison is possible we need not now consider we find in the higher conspicuous differences between pre- sentations which in the lower are indistinguishable or ab- sent altogether. The worm is aware only of the difference between light and dark. The steel -worker sees half a dozen tints where others see only a uniform glow. To the child, it is said, all faces are alike ; and throughout life we are apt to note the general, the points of resem- blance, before the special, the poin*.; of difference. 1 But, even when most definite, what we call a presentation is still part of a larger whole. It is not separated from other presentations, whether simultaneous or successive, by some- thing which is not of the nature of presentation, as one island is separated from another by the intervening sea, or one note in a melody from the next by an interval of silence. In our search for a theory of presentations, then, it is from this " unity of consciousness " that we must take our start. Working backwards from this as we find it now, we are led alike by particular facts and general con- siderations to the conception of a totum objectivum or objective continuum which is gradually differentiated, thereby becoming what we call distinct presentations, just as with mental growth some particular presentation, clear as a whole, as Leibnitz would say, becomes a complex of distinguishable parts. Of the very beginning of this continuum we can say nothing : absolute beginnings are beyond the pale of science. Actual presentation consists in this continuum being differentiated ; and every dif- ferentiation constitutes a new presentation. Hence the commonplace of psychologists : We are only conscious as we are conscious of change. But "change of consciousness" is too loose an expression Gradual to take the place of the unwieldy phrase differentiation diflferen- of a presentation-continuum, to which we have been driven, ^genta- For not only does the term " consciousness " confuse what tkm-con- exactness requires us to keep distinct, an activity and its tinuum. object, but also the term "change" fails to express the characteristics which distinguish presentations from other changes. Differentiation implies that the simple becomes complex or the complex more complex; it implies also that this increased complexity is due to the persistence of former changes ; we may even say such persistence is essen- tial to the very idea of development or growth. In trying, then, to conceive our psychological individual in the earliest stages of development we must not picture it as experienc- ing a succession of absolutely new sensations, which, com- ing out of nothingness, admit of being strung upon the "thread of consciousness" like beads picked up at random, or cemented into a mass like the bits of stick and sand with which the young caddis covers its nakedness. The notion, which Kant has done much to encourage, that psychical life begins with a confused manifold of sensa- tions not only without logical but without psychological unity is one that becomes more inconceivable the more closely we consider it. An absolutely new presentation, having no sort of connexion with former presentations till the subject has synthesized it with them, is a conception for which it would be hard to find a warrant either by direct observation, by inference from biology, or in con- siderations of an a priori kind. At any given moment we have a certain whole of presentations, a " field of con- sciousness " psychologically one and continuous ; at the next we have not an entirely new field but a partial change within this field. Many who would allow this in the case of representations, i.e., where idea succeeds idea by the workings of association, would demur to it in the case of primary presentations or sensations. " For," they would say, "may not silence be broken by a clap of thunder, and have not the blind been made to see T' To 1 This last statement is apt to mislead by implying an active com- parison of several objects ; but that absence or confusion of differences which hides the many is really very different from the detection of resemblances which makes the many one.