§ 5. Improvement of Memory by Practice. — It is certainly true that the exercise of memory in a special direction improves it in that direction. By long practice actors come to learn their parts more rapidly and easily. The same is true of clergymen who learn their sermons by heart. These effects of practice appear to be strictly confined to the special kinds of ideal revival which are exercised. A man who improves his memory for words does not thereby improve his memory for places.

It has been denied that memory can be directly improved by practice. The power of remembering depends on the kind and degree of attention given to the original experience. It has been urged that what is educated by practice is the attention, and not the power of recall. Professor James for instance maintains that "all improvement of memory consists in the improvement of one's habitual method of recording facts."* It is the power of learning, not the power of retaining, which is increased by practice. "I have," says James, "carefully questioned several mature actors on the point, and all have denied that the practice of learning parts has made any such difference as is alleged. What it has done for them is to improve their power of studying a part systematically. Their mind is now full of precedents in the way of intonation, emphasis, gesticulation."There can be no doubt that Professor James is right in assigning increased and better directed attention as a cause of the improvement of memory by practice. It may even be admitted that it is the most important factor. The endeavour to remember is an endeavour to attend; and by repeated and prolonged attention to objects, we not only make the traces more permanent which our experience of them leaves behind: we also bring them into relation with other objects : and so multiply the associations which may severally and conjointly contribute to their revival.

* Principles of Psychology, vol. i., p. 667.

Ibid., p. 664.

But it may be doubted whether Professor James's account of the matter contains the whole truth. According to him, the power of retentiveness is born with each individual as an essential part of his general physiological constitution. It is "a physiological quality, given once for all with his organisation, and which he can never hope to change. It differs no doubt in disease and health; and it is a fact of observation that it is better in fresh and vigorous hours than when we are fagged or ill. . . . But more than this we cannot say."* On this point also we may admit that Professor James is right. But it seems to have escaped his notice that the congenital constitution which gives superior retentiveness in a certain direction is often connected with special interest in this direction. It might be argued that congenital constitution gives power of remembering only by giving the aptitude and impulse for attending. This is at least true in part, if it is not the whole truth. But if it be so, the distinction between native power of retention and that acquired by practice is not so sharp as Professor James supposes.

* Op. cit., p. 664.

Admitting that native power of retentiveness is a fixed quantity, unchangeable by exercise or education, we may none the less demur to the conclusion which Professor James appears to draw from this theory. To maintain this conclusion, he stands in need of an additional hypothesis — the hypothesis that all mental dispositions corresponding to particular objects are absolutely and not merely relatively distinct. If different dispositions have common factors; if they partially interpenetrate each other, then the experiences by which one is formed will have already done part of the work requisite for the formation of another.* But the facts of association show that the dispositions corresponding to similar experiences must be regarded as partially the same. This is peculiarly clear in association by similarity. One man, by some similarity in his personal appearance, may remind me of another; I may not discover, even after careful scrutiny, what the point of resemblance is. It has not formed a separate link of association. Yet the disposition left behind by my experience of the one person has been reexcited by the sight of the other. The dispositions left behind by the two experiences must therefore have some common factor. They must partially interpenetrate. In general, so far as the revival of similars by similars is possible, there must be a partial coincidence of mental dispositions. The same applies to association by contiguity. If recalls y because b and c have been associated, the dispositionleft behind by b must be partially reexcited on the occurrence of; the dispositions left behind by b andcannot therefore be absolutely independent.

* Probably James does not really mean to deny this ; but if so, his language is misleading.

Just in so far as this interpenetration of mental dispositions exists, the exercise of the memory for certain experiences will improve the memory for analogous experiences. When a man has made a certain amount of progress in the learning of a foreign language, further progress is facilitated, just because he has become familiar with certain general characteristics of the language, which do not need to be learnt over again for every particular case. Of course it does not follow that memory in general is improved by its exercise in this or that particular direction. The progress will only extend to analogous experiences in precise proportion to the degree of analogy. Exercise of the memory in the study of languages will do little to improve it for the retention of chemical formulae.

§ 6. Memory and Past Time. — There is one most important aspect of memory which we have not touched upon. When we remember objects or events, we often apprehend them as having been presented to us in our past experience. It is not necessary or convenient to discuss this point now. It is part of the general question of the origin and development of the ideal representation of timerelations, which will be discussed in the chapters on "The World as Ideal Construction" and "The Self as Ideal Construction."