book" (p. vii). Lectures framed to supply in minimum time the needs of wartime officers of the R.A.M.C. might possibly have been made the foundation of a useful contribution to medical psychology: their use as the basis of a popular account of remembering and forgetting is hard to understand.

The body of the book is divided into nine chapters of which the first deals with the question "What is memory?" and the last is entitled "How we forget." In between are three chapters on mental imagery, "the apparatus of the memory," and four on dreams. The discussion of mental imagery is continued in an interesting appendix of four chapters that stamp in the impression that, for the book, a better title than "Remembering and Forgetting" would be "Imagery and the Dream." The study of memory is often side-tracked into the image-hunt, but four chapters on the dream in a short work on memory needs explanation. Part of that explanation is the peculiar interest of the dream in psychopathology; but there is another reason. In "the structural study of the dream" the author sees "another way of studying the relation between image and meaning which has not been given the attention which it deserves" (p. 66).

Visual imagery forms the basis of discussion and illustrations drawn from the author's own experience of this form of imagery are particularly interesting. The mutual intolerance of people who use different forms of imagery is noticed in several places and is dealt with at some length in the appendix on "The Intellectual Respectability of Muscular Skill" (pp. 220 f.). Outstanding work on "Varieties of Mental Imagery" is mentioned and the monograph of Dr Mabel Fernald1 is specially commended (pp. 21 f.). Kinaesthesis is dealt with at some length, the author dwelling on and apparently accepting Professor Washburn's conclusion that kinaesthetic imagery is in reality "movement sensation resulting from the actual slight performance of movements" (p. 26).

""

Considering the function of imagery we find "the chief function of imagery seems to be the conveyance of meaning" (p. 44) and "the image plus its meaning is nowadays generally known as the idea" (p. 48) This leads to a discussion of "the relative independence of image and meaning" (p. 48) and ends in consideration of the important question of "imageless awareness which for the author would seem to be awareness with the minimum of imagery" (p. 58 n.). Washburn's theory is apparently accepted: "Imageless thought would occur when the problem set... was comparatively easy...the thinker though actually solving a question the apparent difficulty of which would impress the non-philosophical outsider, might do so without being clearly aware of the mechanisms which he employed though actually these might be the movements of speech muscles or of those used in gesticulation.... Possibly the professional thinkers who acted as subjects in the experiments which are claimed to have established the existence of imageless thought were so accomplished that the problems set them had been half solved months or years before they appeared in the thought experiments. On the theory which we are considering the movements which accompanied such 'imageless' thoughts would have been feeble, and, like all kinaesthetic experiences, difficult to localise and to name" (p. 65). References are given to several discussions of the question, the last mentioned being that of Professor R. S. Woodworth2. Now,

66

1 "The Diagnosis of Mental Imagery," Psychological Review, Monograph Supplement, No. 56.

2 "A Revision of Imageless Thought," Psychological Review, 1915, xxii. 1–27.

to prove a negative is impossible. Hence in the long run the 'imageless' thinker must be content with the definite declaration: I am aware of the presence of meaning unaccompanied by any awareness of necessary accompanying imagery; and remain an unbeliever in the doctrine of the necessity of the image until the exponents of the doctrine can convincingly convict him of error. It is possible that in essence the idea is meaning; that this meaning may or may not be accompanied by imagery and that, instead of the image being essential for meaning, it may be but tentative experiment in ways and means of conveying the idea (i.e. the meaning) to another, or of using it in some other way. Such a supposition would seem to receive inconsiderable support from experiments such as those of T. V. Moore1 in which the reaction time for awareness of 'simple meaning' is found to be considerably shorter than that for awareness of imagery.

In 'imageless thought' meaning is, at least, the dominating partner, and imagery, if present, is highly elusive. At the opposite pole stands the dream with its vivid imagery and elusive shifting manifest meaning, sometimes, possibly always, screening a more elusive latent meaning. It is to the dream. that the author turns in his search for the relation between image and meaning. "Perhaps...the wildest, maddest dream is merely a conglomeration of actual memories" (p. 69). "Freud goes so far as to say that all dream images, whether recognised as composite or not are in reality made up of memories and that not only is their combination effected according to definite principles but that in the dream the combination itself performs definite functions of great biological importance" (p. 79). The facts and theories relating to these 'definite functions' are set aside as outside the scope of the book, but we are shown the difference between directed and free association and invited to accept the doctrine that in 'free' association "unconscious directive tendencies take over the function of guiding our thoughts and that in this way by freely associating from any part of the manifest content of our dream we can discover the underlying latent material of which it is the representative in consciousness" (p. 80). A method of dream analysis is outlined and introduces a short account of psychoanalysis.

The stimulus theory of the dream is dealt with as the only alternative to Freud's theory and is dismissed as inadequate. In many cases where a stimulus is clearly recognized on waking the stimulus had been present for many nights before the particular one on which it 'caused' the dream: it "usually does little more than to ignite a train previously laid" (p. 75) and, quoting from Nicoll, "the physical disharmonies do not in themselves explain the dream. They act as sensitizers" (p. 76). The argument is not conclusive. The question is not: What is the material used in shaping the dream? but: Would there have been this dream if there had not been this stimulus? It seems reasonable to conclude that dreams obtained by experimental means such as the "tensors" and "detensors" of Cubberley's work would not have occurred in the absence of the stimulus and that the nature of the memory revived in the dream is controlled by the nature of the stimulus. At the other extreme there are, possibly, dreams in which the stimulus is from within the mind and all material

1 "The Temporal Relations of Memory and Imagery," Psychological Review, 1915, xxn. 177-225.

"The Effects of Tensions of the Body Surface upon the Normal Dream," British Journal of Psychology (Gen. Sect.), 1923, xш. 243–65.

used in elaborating the dream is mental: the nature of the memories revived being wholly controlled by the nature of the mental stimulus. Possibly the true 'wish' dream and the true 'physical stimulus' dream are not irreconcilable alternatives but extreme cases of the dream in which both internal mental stimuli and external physiological and physical stimuli act upon the complex 'retent' in mind and conjure up a jumbled memory having hallucinatory

vividness.

In Chapter vi we have the familiar summary of Freud's theory of 'dream work' and in Chapter VII some account of "Rivers's view of the dream." "The undisguised and terrifying dream of battle...the nightmare and the undisguised sexual dream...led Dr Rivers to contest at several significant points Freud's explanation of dreams, more particularly at those concerning the censorship, the alleged sleep preserving function of the dream and the wish fulfilment theory.... As Rivers views it the dream arises out of mental conflict and is an attempt...to solve a problem" (p. 102). With Rivers's criticisms and his doctrine of levels of experience the author appears to be in agreement. He also throws in his lot with those psychologists who deny that "the dream work" is, in any essential, different from activities of the ordinary everyday waking consciousness. He writes: "It is sometimes claimed that the processes of the dream work are unique, that they have no parallels in waking life. This is inadmissible. Freud's view: 'It is condensation that is mainly responsible for the strange impression of the dream, for we know nothing analogous to it in the normal psychic life accessible to consciousness,' is expressed too absolutely" (p. 109). He then argues that in the 'generic' image, portmanteau-words' and the cartoon we have waking examples of condensation; that dramatization is common in waking life: "many visualizers attempt the solution of almost all difficulties which require forethought by picturing different actions and their results" (p. 114); that "secondary elaboration is only the customary manner of interpreting any object or thought which has been imperfectly apprehended" (p. 114), a fact that has been demonstrated over and over again in experimental work on perception and on memory, and concludes "the dream, therefore appears to be a mental structure the constituent mechanisms of which are not different in kind from those which characterize the mental events of waking life. It is the reciprocal interplay of these mechanisms, the altered emphasis which each of them receives, and their comparative freedom from the dominating directive tendencies of the day time which combine to make the dream the enfant terrible of the well ordered personality, and the delight of the modern psychologist."

Coming closer to the problem of remembering and forgetting, in Chapter IX, "How we forget," we find the "older psychology," including the work of Ebbinghaus, treated very briefly and somewhat cavalierly and then the part played by the affect in forgetting is considered at length. Freud's doctrine of repression and Rivers's discrimination between 'witting repression' and 'unwitting suppression' are dealt with, while Rivers's attempt to indicate a physiological explanation of forgetting by analogical comparison with facts and theories associated with epicritic and protopathic sensation, the cerebral control of the optic thalamus and the 'mass-reflex' of the divided spinal cord is favourably reviewed, subject to a note that "the validity of [Rivers's interpretation of the facts] is not granted by all physiologists" and a reference to Metcalf's paper1. Finally, replacing Rivers's idea of the fusion of memories by

1 Psychological Bulletin, 1921, xvIII. 4, 181–202

the idea of 'embodiment,' the author puts forward the following as a provisional classification of forgotten experiences:

1. Embodied (6) Significant but completely congruous with
the personality.

2. Exiled

3. Superseded

Forgetting of Class 1 (a) “may conceivably be due to physiological decay" (p. 166), but if all experience is indefinitely retained this explanation must be rejected. The author however is a little sceptical of the doctrine of complete retention and writes "in a collection of my own dreams I have found memories of very early experiences of childhood...but I have not discovered any whichdid not prove to be part of the associative fringe of some very significant incidents. And it may conceivably prove to be true that only those incidents which for some reason are disembodied...form the material for the hypnotist's striking performances" (p. 167). In Class 1 (b) we have the "obliterating effect of congruity upon past experience." Class 2 comprises the 'repressed' experiences of psychopathology and Class 3 obsolete memories that "do not appear to be held out of consciousness by an ever present resistance...[but] are seldom invited to enter" (p. 174).

Except in Chapter 1 and portions of Chapter IX the author has written of imagery and the dream rather than of memory. The imagery used in recall is of far less importance in the study of memory than the reliability and amount of the recall, while to classify the dream as memory would seem an error unless 'memory' is to be made co-terminous with thought. There is a sense in which the dream is memory, but in exactly the same sense the falsehood "I visited Sirius last week and discussed the matter with Julius Caesar" is memory. The author has expressed it thus: "The statement [that it is memory] is true rather of the material and the constituent patterns than of the main design of the dream" (p. 69). We would suggest that it is essential that classification of the dream should not exclude this main design. If Freud is right and dreams are 'wish' fulfilment they would seem to rank with the free associative, imaginative thought of 'day-dreams' and 'castles in the air.' If Rivers is right and they are attempts to solve a problem they would seem to rank with the directed, selective thought of constructive imagination. If, further, there are dreams that fit neither theory they would seem far more closely allied to hallucination than to either the free associative thought of reminiscence or the controlled, critical thought of recollection. Memory is tinged with a temporal signature that places the actuality in the past: the temporal signature of the dream is now. As an experience the dream has more in common with the percept than with memory, but its relation to reality is not that of the percept. As its relation to time is not that of memory and its relation to reality is not that of the percept, the dream can scarcely be classified as either the one or the other, and would seem to be much better placed either as ballucination or as imagination. The author was very close to this view when, in discussing the processes of dream-work, he wrote: "The evidence, indeed, makes it extremely probable that they are operative not only in fashioning the dream but in the work of the waking activity of creative imagination" (p. 87).

R. J. BARTLETT.

Group Tests of Intelligence. By PHILIP BOSWOOD BALLARD, M.A., D.Lit., London. Hodder and Stoughton, 1922. pp. x + 252.

Dr Ballard is one of those who have firmly grasped the indubitable fact that "intelligence tests" have come to stay. Once or twice in the course of a generation there emerges in the conduct of human affairs a factor which, in spite of all hostility and suspicion, calmly and inevitably developes, leading eventually to a complete overhauling of the principles and methods applicable in the field to which it belongs. The procedure of testing intelligence on the basis of age-performance by methods such as those described by Dr Ballard in this book (and in his previous book, Mental Tests) is such a factor. There is little doubt that it is destined ultimately to revolutionize our ideas on education and on the fitting of the child to bear his share in the national life in the position most appropriate to him by reason of the type and grade of his native mental ability.

Criticisms of intelligence tests are mainly academic and a priori in kind. They are usually based on the appearance of the tests, and not on their results. Yet it is their results as empirically observed, which determine for the psychologist the applicability and suitability of his tests, and by their results the tests must be judged. The only thing which really matters is whether the tests do in fact perform successfully their task of grading children (and others) accurately according to their capacity for being educated and for applying what they have gained by education. Though by no means perfect, the tests are already performing this task well (far better, indeed, than any other method of the past) and, as Dr Ballard points out, they are performing it better every dav.

The book under consideration falls into four well-defined sections. Dr Ballard first gives an account of the standard types of group tests derived from the American experiments (notably the wholesale testing of the American Army). He then passes on to a general survey of group testing in England, and in particular, of the types of tests which he himself has used. There follows a discussion of the nature and limits of intelligence. Finally, there is a valuable section dealing with the elements of the statistical technique necessary to a proper collation and interpretation of the results of the tests.

Dr Ballard's account of the development in England and America of methods of measuring intelligence is clear and interesting, and forms what is perhaps the most useful summary of these methods at present obtainable. The chapter on Dr Godfrey Thomson's well-known "Northumberland Tests" will be of particular interest to English readers; while the account of the author's own tests provides valuable and suggestive additions to the armoury of diagnostic weapons now available.

The chapter on the nature of intelligence affords material for what will always be a source of keen discussion. As Dr Ballard makes clear, the question is, of course, mainly of academic rather than practical interest so far as "intelligence tests" are concerned. All who are familiar with the practice of them will agree that the tests measure something, but the ability to frame a precise definition of this "something" is irrelevant to the question of the practical value of the tests, which can be decided only by their capacity to perform the task to which attention has been previously drawn, namely the selection of children according to their educability.

With Dr Ballard's remarks on the limits of the growth of intelligence the