Plato envisaged the need for an examination system not essentially different from ours . of his potential guardians he wrote : we must find out who are the best guardians &amp;hellip; . we shall have to watch them from earliest childhood and set them tasks &amp;hellip; . we must also subject them to ordeals of toil and pain and watch for ( their ) qualities . and we must observe them when exposed to the test &amp;hellip; put them to severer proof than gold tried in the furnace &amp;hellip; . if we find one bearing himself well in all these trials &amp;hellip; such a one will be of the greatest service to the commonwealth as well as to himself . the purpose of Plato &apos;s tests was to be of service to the commonwealth as well as , and more than , to the individual . he held that social life depended on specialization of function and he believed that each person was best fitted by congenital constitution and education for a particular role . education not only helped to train a person for his particular function , it also revealed native constitution : response to education predicted capacity for future achievement . the educational system was inevitably also a selection system , and Plato &apos;s tests were only more refined instruments of screening than the educational process itself . this dual function of educational systems - to educate and to assign people to roles - is a perennial source of difficulty . both functions are necessary , but it is not easy to carry them out together , and the temptation is to welcome one and to reject the other . Dr Wiseman refers in his foreword to those who , rightly valuing education , reject the necessity of selection , and take up the position he condemns as therapeutic extremism . Plato may be accused of having gone to the other extreme , for it seems that having selected his guardians he has little interest ( in the republic ) in the education of the rest . the American public school system has accepted the function of education and on the whole rejected that of selection : selection is left to the college and the university , to the M.A and the Ph.D stage rather than to anything resembling the 11-plus and the G.C.E . in England 11-plus selection has been deplored because of its adverse effects on education in the primary school . a distaste for the selection function may be discerned also in the Crowther report &apos;s desire , on behalf of secondary schools , to make the G.C.E a school-leaving and qualifying examination and to dissociate it from the selection of university students . distasteful though the function of selection may be , however , it is one which the educational system can not escape , for as Plato pointed out educational achievement is not only the means to , but an indispensable index of capacity for , service to the commonwealth . the screening function has not been pressed upon educational systems with equal insistence at all times and in all places . in so far as social and vocational roles are predetermined by race , caste , or family , the assessment of the abilities of the individual is of less significance . the possibility of selection on the basis of individual differences presupposes some degree of social mobility , and it is arguable that it is at times and places where social mobility is greatest that the interest in examinations and tests has been strongest . Mr Morris has noted that imperial China , with its dictum . employ the able and promote the worthy , developed a highly complex system of examinations , whereas in the comparatively closed society of medieval Europe the interest in examinations was limited and sporadic . Bentham , intent on widening and improving recruitment to the civil service , was characteristically interested in examinations . the development of public examinations since the 1850&apos;s has been closely connected with the extension of elementary , secondary , technical and university education and of access to the crafts and professions . the more recent institution of the diploma in technology and the work of the associated examination board are obviously related to the increasing esteem which technical skills and abilities command . Plato in fourth century Greece noted ( with disapproval ) the similar upward mobility of craftsmen and its connection with an interest in qualifications - with philosophy if not with the doctorate of it : philosophy &amp;hellip; is dishonoured by unworthy interlopers &amp;hellip; when any poor creature who has proved his cleverness in some mechanical craft sees here an opening for a portentous display of high-sounding words and is glad to break out of the prison of his paltry trade and take sanctuary in the shrine of philosophy . for as compared with other occupations , philosophy , even in its present case , still enjoys a high prestige . values in educational achievement change . Plato valued philosophy and despised crafts that enslaved men ; we value technologists more than philosophers ; but whatever kind of specialist one has most use for one seeks to select and promote ; and the greater the freedom to rise the more one uses tests and examinations to refine the screening function which the educational system performs . it is because democratic ideals and economic needs at the present time put a premium on the emergence of ability that we are specially interested both in education and selection . as new kinds of service to the commonwealth are demanded , new kinds of education have to be established , or old kinds have to be adapted ; and examinations at once define and support them . it is often said that examinations maintain standards in education ; it should not be overlooked that they sometimes help to create them . the diploma in technology not merely preserves standards , it sets objectives and stimulates the effort to achieve them . the reform of university examinations in the nineteenth century did not preserve standards , it helped to establish higher standards of education for service to church and state . examinations defined standards which supported the development of secondary education for girls in the same century and that of the maintained grammar schools in the twentieth century , and if they did not create sixth forms in these they at least stimulated their growth . the examination of general studies is helping to produce a situation in which such studies have a greater chance of survival in the sixth form . it is the value systems of the commonwealth which likewise confer on examinations their force as incentives to learning . Plato alone - and he in theory only - removed the economic incentive to learning . his guardians were to be motivated in their arduous studies by disinterested service to the commonwealth : they alone of all the citizens are forbidden to touch and handle silver or gold . it is hardly to be supposed that the incentives he proposed would appeal strongly to the candidate in 11-plus , G.C.E or university examinations : whenever we find one who has come unscathed through every test in childhood , youth , and manhood , we shall set him as a ruler to watch over the commonwealth ; he will be honoured in life , and after death receive the highest tribute of funeral rites and other memorials . it may be true that pupils do not always have clearly in mind the long-term advantages of passing examinations , and that it is rather the teacher or parent who is moved by them . even so the incentive which is felt by the pupil through them is derived ultimately from the demands of the commonwealth for particular kinds of developed ability : the examination merely focuses these demands . the pupil &apos;s educational values are at least indirectly those of the society in which he will find his role . it may be suspected that the G.C.E candidate , for example , has a shrewd idea of the relative values of passes in English language , scripture knowledge , physics and art . the trends in the number of entries for G.C.E examinations to which Dr Petch draws attention suggest a quick appreciation of the social and economic evaluation of different studies . the most radical method of increasing social mobility so far devised has been the use of intelligence tests . the education system educates and selects , but as we have seen the two functions are not easily reconciled . if selection can interfere with education , so can education , or the lack of it , interfere with selection . it has long been recognized that there are mute inglorious Miltons - mute and inglorious because uneducated and a fortiori unselected . in twentieth-century England there may be few who have not had the opportunity of education , but opportunities have varied ; and as parents , teachers and communities can not be equalized opportunities are long likely to vary . yet democratic ideals and the economic need to exploit the scarce commodity of talent alike impel us to seek out ability even where it has not been fully developed by education . no reputable psychologist has claimed that he can measure some pure hypothetical intelligence which has not been affected by environment and education , but psychologists have been highly successful in constructing tests which are less affected by differences in educational opportunity than are most tests of educational attainment . the psychologists &apos; success has naturally been looked upon with disfavour by those who could command educational opportunity though not intellectual capacity . their tests have also been the object of abuse from those who believe that a person is made by collective society and who can not on ideological grounds accept that the individual ( or for that matter wheat ) has any characteristics which he does not owe to society . neither group objects to selection or to selection tests : each merely wishes to select persons who meet his own specifications , which are not solely in terms of the qualities of the individual . it is to be hoped that the uninformed and doctrinaire attacks on the judicious use of intelligence tests will be stoutly resisted . they are not a panacea , but they can be highly competent instruments for use in the open society . it is significant that , as Dr Wiseman points out , such tests first became widely acceptable in the American army in the first world war , when it was acceptable that military rank and function should depend on individual rather than social , economic or racial differences . tests and examinations are instruments which a free and open society has need of . it must be admitted that selection on the basis of the abilities of the individual has been criticized by not illiberal persons . there are dangers in the selection of the able but badly educated . T S Eliot has suggested in effect that an &amp;eacute;lite may have intelligence but lack culture . the emergence of angry young men may be taken to support his argument . he probably underestimates , however , the assimilative power of education . men do not remain young , or necessarily angry , and their children , faced with fewer obstacles to selection , may be more open to the influences of culture . the evidence in the Crowther report shows that the first generation of the more educated seeks still more education for its children , so that culture as it were accumulates at compound interest . the selected have also been depicted as a meritocracy . one can sympathize with the guilty feeling that it is in some ways distasteful that some people should be endowed with greater gifts than others . it might have been better if it were true that all men are equal - though it would detract from the interest of , for example , the Olympic games . the facts being what they are , however , it is incumbent on the objectors to meritocracy to say what alternative they would propose - aristocracy , plutocracy , caste , nepotism , party membership , or what ? until a rational non-escapist alternative is offered , the only way seems to be to make intelligence tests , examinations and other instruments of selection as effective as possible for their purposes , while minimizing as far as possible any harmful effects they may have on the main function of the educational system , that of education . there is no denying that the inevitable process of selection can have deleterious effects on the more essential process of education . at every stage of the educational process where selection becomes prominent , the latter affects the former , usually in some respects to its disadvantage . Dr Wiseman has discussed in particular the educational effects of 11-plus selection , where the problems have been recognized and fully debated . 