it certainly cannot be, but we venture to think that the influence of biology on the psychological problem is shown more truly by a new spirit of investigation within psychology itself than by any attempt to graft the findings of psychology on to those of biology, or to restrict the method of the one to that of the other.

We saw that biological conceptions dominated the psychology of Herbert Spencer and that their influence was apparent in the later editions of Bain. A paradigm for the systematic development of psychological theories from basic conceptions had been afforded by the continental writers, and biological conceptions furnished a new foundation for such a systematic treatment.

Psychology in England may be said to have entered upon a new era with the publication of Prof. James Ward's article in the Encyclopaedia Britannica in 1886.1 While profoundly influenced by the traditions of the English Empirical school, Prof. Ward owed much to the line of continental thinkers whose influence was noticed in the case of Hamilton. His psychology may be styled philosophical. Nevertheless he sets forth psychology an an independent body of doctrine the data for which are to be found in experience, that is, in all facts whatsoever so long as these are studied from the point of view of an experiencing individual—the subject of experience. By stressing the subject, Prof. Ward rescued the trend of psychological opinion in England from passing from Associationism to any new form of Presentationism. For Prof. Ward the unity of the subject underlies all the various operations of mind. The faculties of Reid are replaced by differences in the kind of object whereon the activity of the subject is exercised. Psychology is biological in that it studies a life story, but it is mental life that it studies, and studies from within, from the standpoint of the experient. The

1 Incorporated with modifications in a new book, Psychological Principles, 1918.

genetic treatment of psychology by Prof. Stout may in the same sense be termed biological. He defines psychology as the science of the development of mind'. (Analytic Psychology, vol. i, p. 9.)

If the influence of biology on psychology is to be sought in the treatment of psychology as a study of mental life, we may consider the difficulties of the memory problem noticed in the previous chapters from this point of view. What follows must be regarded as the writer's attempt to work out the memory problem from the standpoint of a psychology wherein the conceptions of process, function, structure, growth, decay, organization, and development have their place. That much of its tenor has been derived from the psychology of Prof. Ward and Prof. Stout will be evident. (a) The nature of the memory-image.

Our study of Behaviourism and of New Realism showed us that the existence and nature of the memory-image was a crucial question in the psychology of memory. We saw in the historical survey that for some writers the image differed from the original of sense in kind, while for others it differed in degree only. Also, that while some regarded it as a persistence of the vestiges of sense, others regarded it as a reproduction called forth by a special occasion. We may, then, consider first the nature of the memory-image.1

The notion of mental life itself connotes change, succession of events; it also connotes continuity of process. We cannot easily conceive that even the simplest forms of life would present us with a single line of changing events, but believe that there would be a multiplicity of processes, such that, if we took a cross-section at any moment in the life, we should

1 No effort will be made to relate the theory here sketched to any physiological theory of the nature of an image, such as the theory of Prof. M. F. Washburn or that of Prof. Dunlap. It has not seemed to the writer that the psychological problem would be helped by such an attempt. The' explication of conceptions' is a prior psychological need.

find this process beginning, that one ending, that one running its course; further, that wherever we took the cross-section we should find a weighted present'. The impetus of the processes which had run their course up to that point would tell on the character of the cross-section. If we use the term ' retentiveness' to denote the character in virtue of which mental processes are continuous, and in virtue of which the present process is weighted by those which have preceded, retentiveness' would seem to be involved in the very conception of mental life.

It is not easy to group the processes which constitute life into different kinds, but in view of the functions of life we seem justified in recognizing at least two groups of processes, those whose function is knowing and those whose function is doing cognitive and conative processes. Affective processes seem to the writer to be a third group with a specific function in life, a function roughly denoted by the term 'appraisement '. In the early stages of life these processes are not clearly distinguished from one another, and throughout life their co-operation in function may make their distinction one from the other difficult.

Retentiveness as a character of mental life will apply to all mental processes. It is necessary, however, to examine the conception a little more closely. We require to recognize something more than the character of temporal continuity and the weighting of a given process by those which precede it. It is not only the immediately preceding processes which influence the character of a cross-section, but also those which were in the past'. The effects of repetition, which are seen as familiarity in the case of cognition and as facility in the case of conation and the affective processes, testify to ' retentiveness' in some further sense. We thus have to find a place for some conception of persistence. We cannot fall back on any modification in material structure as an abiding link to support change in function, nor on any persisting

features of structure as a support for continuity in function. All spatial conceptions fail, and our thought trained on spatial relations is baffled; the very notion of 'persistence is permeated with spatial significance. What is it that abides in mental life? Nothing. No ghost processes. No operations of minimum intensity. Yet there is a sense in which there is' persistence' in mental life. A succession of processes of the same kind may be regarded as continuous, and any one selected for study is' weighted' by what precedes it. Further, if we consider the function of the processes we can say that the later ones carry on the function of the earlier ones. E.g. consider the series of cognitive processes relative to the sound of a steam whistle. The sequence of processes can be considered as the continuance of one process. It is the differentiation into moments rather than the recognition of continuity that is the work of thought. We should say there was awareness of one long sound. Here then there is persistence in respect of function.

If we apply the notion of continuity of function to processes of the same character, we can conceive how, despite temporal discontinuity, the repetition of a process may be regarded as a continuation of an old process. If the engine-driver reopens his whistle valve after two or three minutes' silence, we may regard the processes in the hearer as continuing the function of the old processes. We do not need to think of those previous processes in the hearer as persisting, as being anywhere in any sense whatever. It is enough that in considering the mental events in the life of this individual, we cannot leave out of account the fact that those previous processes took place, since the present function implies them. To put it differently, the 'now' of a life in which the old processes took place and the 'now' of a life in which they did not take place would not be the same. In this sense the old processes are retained, and a mental process of a given character may in respect of its function be said to have a life story. Facility and familiarity

testify to its progress. In illustration we may take the sound value of some given combination of vowel and consonants in an unknown foreign language which an individual hears all round him. The life story of the sound would show later impressions carrying on the work of earlier. From being a sound lost in the mass of strange sounds, by repetition it gains in definiteness, until it stands out as distinguishable and finally is experienced as familiar. A corresponding story of growing facility could be made out from the continuity of attempts to pronounce the sound in question. So far persistence has been thought of as the direct continuity in time of processes of the same character or as the repetition at intervals of time of processes of the same character. In both cases the persistence is continuity of function. This then is a fuller interpretation of the character of 'retentiveness'. It is an interpretation which applies to all forms of mental process.

We have to consider a manifestation of retentiveness, the recognition of which is bound up with the recognition of selective activity. There is a persistence and continuity of function which belongs only to cognitive processes, and belongs only to these in virtue of the relations into which they have been brought by conative effort. When all processes are qua processes activities, it may seem unnecessary to conceive of any group of processes as active in a special sense. Perhaps this is partly why Prof. Alexander chose to term all mental processes conations. But the recognition of conation as the name for a special group of processes, even if it were not borne in upon us by an analysis of self-experience and the testimony of language, would seem to be required by the investigation of the processes of cognition. At this point it is no longer possible to avoid referring to the subject and object of consciousness, though in view of their epistemological implications it is to be wished that both terms could be eliminated from psychology.