THE invitation sent out by the National Union of Scientific Workers to all those who have made science their vocation, to assist in building up an organisation which shall be fully representative of their various interests, may appear to some to be superfluous. They may argue that the functions which it is proposed this representative body should perform come within the scope of the legitimate activities of existing bodies, the various learned societies, propagandist bodies like the British Association and the British Science Guild, and the professional institutions the members of which are engaged in the teaching and practice of science. Others, while prepared to agree with the statement that none of the existing bodies is fully representative of science and the scientific worker, may feel that this is an advantage rather than a disadvantage, in that it is conducive to the freest expression of the will of the individual. They may fear that the establishment of a code of professional ethics, for example, might result in the growth of a narrow professionalism deadly to the spirit of science. A hundred years ago similar objections were raised to the formation of the British Medical Association. Some qualified physicians, surgeons, and apothecaries on one hand, and all the quacks on the other, regarded this body with the greatest disfavour, the former because they resented the implication that the existing bodies were not allsufficient and wished to safeguard their right to control their respective branches of the medical profession, the latter because they were fearful of the material consequences to themselves. Yet it cannot be seriously suggested that the peculiar form of professionalism which was established mainly through the initiative and instrumentality of the British Medical Association has not been of the greatest advantage to the members of that profession and even more to the public. It must be acknowledged that the type of professionalism which insists that the results of ameliorative research should be made available to the whole world, which insists also that the discoverers themselves shall not derive any immediate and direct pecuniary benefit from them, is expressive of the highest ideals of service and calculated to attract to the profession some of the finest spirits of the age. Neither can it be said that the prestige of the Royal Society of Medicine, the Royal College of Physicians or the Royal College of Surgeons, or the faculties of medicine of the universities of Great Britain suffered through the activities of the democratically constituted body: actually their prestige was enhanced. The medical profession is practically a self-governing body, members of the profession predominate on the General Medical Council, and the Government puts large funds at the disposal of the Medical Research Council, most of the members of which, and the chief administrative officer, are also members of the medical profession. Moreover, they act in an executive capacity, and not merely an advisory capacity like the scientific members of the Committee of the Privy Council for Scientific and Industrial Research.