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it appeared, needed to be mixed (girls often wanted anexcess of boys) and universally friendly. Boys were moreinterested in avoiding fighting, bullying, and knives; andboth sexes demanded optional classes in handicraft, art,and drama, and discussion groups. Dancing and musicwas often mentioned, with some masculine dissent aboutjiving. On organisation, girls merely wanted the club tobe run by a handsome young man, but the boys usuallywanted to take part in a club committee. Weekend

outings were desired equally by both.Mrs. Stewart declares:

" The increase among grammar school and the decline

among modern school pupils in the importance which theyattach to expressive activities such as singing, playing thepiano, painting, acting, etc. suggests that over the last ten

years, grammar schools have been more successful thanmodern schools in fostering these pursuits to the point thatthey become worthy of mention as a favourite out of schoolactivity."We may draw comfort, on the whole, from Mrs.

Stewart’s conclusion that the matter and manner of

replies revealed a greater maturity and confidence inchildren today than ten years ago. But there is certainlyno room for complacency.

OCCAM’S RAZOR

STUDENTS will be amused to learn that an erudite phrase,beloved by so many of our teachers, has proved to be amisquotation. Entia non sunt multiplicanda praeternecessitatem was used recently by a correspondent, buta fellow peripatetic 2has suggested that scholarly precisionshould lead to its rustication.

Many of us are familiar with the eponymous title,without being certain who or where Occam was, andprobably not knowing why the phrase was called a razor.William of Occam (Ockham in Surrey) was a Franciscanwho lived in the early part of the 14th century. Educatedat Merton College, Oxford, he was a pupil and later rivalof Duns Scotus and had tremendous influence in scholastic

thinking for many centuries. He revived Nominalism, hada protracted battle with Church and Pope, and was knownas the Invincible Doctor (" if the Gods used logic, itwould the logic of Occam " 3), or the Singular Doctor-perhaps because one of his most famous expressions begansufficiunt singularia.4

In 1746 Condillac wrote, " At the beginning of the12th century, the peripatetics formed two branches, theNominalists and the Realists ... The former insist onthe principle that nature makes nothing in vain. This

principle is called the razor of the nominalists." ó His" nash of Gallic wit " was translated from rasoir desnominaux to Novaculum Nominalium in the late 18th

century, and then to Occam’s razor, instead of theNominalists’ razor, by Sir William Hamilton in 1852. 11

The Law of Logical Frugality is a philosophicalprocedure: neither more nor more onerous causes are tobe assumed than are necessary to account for the

phenomena. Hamilton called this by a new name, the Law1. Lancet, 1960, i, 1126.2. ibid. p. 1246.3. Mark of Beneventum (quoted by Thorburn).4. " Sufficiunt singularia, et ita tales res universales omnino frustra

ponuntur."5. Condillac, Etienne Bonnet de, 1715-80, French philosopher. Essai

sur l’origine des connaissances humaines, 1746. (Oeuvres Philo-sophiques de Condillac (edited by Georges le Roy); vol. I, p. 49. Paris:Presses Universitaires de France, 1947.

6. Hamilton, Sir W., 1788-1856, professor of logic and metaphysics atEdinburgh University. Discussions on Philosophy and Literature;p. 590. London, 1852.

of Parcimony 7; then he said it was synonymous withNovaculum Nominalium (and hence with Occam’s razor),and that it could be expressed as entia non sunt multi-plicanda praeter necessitatem-a phrase first used in thisexact order of words in 1654 by Clauberg of Groningen 8about three hundred years after Occam’s death. Occamwrote pluralitas non est ponenda sine necessitate,9 whichmeans (that in giving explanations) we must not supposethat more things exist than we have evidence for; he alsowrote frustra fit per plura, quod potest fieri per pauciora.1OIn their contexts, these were the " razors " which Occamused to shave off superfluous things, and although thephrase attributed to him (beginning with entia) couldnot be found after a meticulous scrutiny of medievaldocuments,8 the implication is not really very different.No doubt Hamilton’s medical colleagues at Edinburgh

University found it useful to incorporate this learnedinaccuracy in their lectures, and so the saying spreadgradually into medical as well as philosophical teaching,and is still given in a vast transatlantic publication.HA Law of Logical Frugality dates back at least to Aristotle,whose followers were known as his peripatetics, and it isappropriate that one of our peripatetics has drawn atten-tion to the myth. In clinical work we would do well tostick to something simple like " don’t make two diagnoseswhen one will do ", though if we must use our Latin, letus quote Occam correctly as pluralitas non est ponenda sinenecessitate, or frustra fit per plura, quod potest fieri perpauciora. What if some Torquemada at a Royal Collegeshould ask for Occam’s tag ? If you tell him accurately,and he denies your answer (because he has not read hisLancet), it will be well to smile sweetly and allow him tocorrect you when you say a little knowledge is a dangerousthina.

INJURY AND ABSENTEEISM IN SMOKERS

THE association between cigarette-smoking and res-

piratory disease has been much investigated, and nowLowe 12 has examined the smoking problem at anotherangle. The frequency of attendance at ambulance roomsfor injuries, and the frequency of absenteeism, among 3341male employees of a large company were related to theirsmoking habits. When these men were classified accord-ing to age and the amount of tobacco smoked, it was foundthat in each 10-year age-group cigarette-smokers hadmore injuries treated than non-smokers; moreover, menwho smoked heavily tended to have more injuries treatedthan those who smoked lightly. A similar relation wasdemonstrated between cigarette-smoking and absenteeismfor medical reasons, but not between cigarette-smokingand absenteeism for non-medical reasons. The number ofpipe-smokers was too small to warrant analysis. Therelation between smoking and injury was much moredistinct in younger men (under 35 years) than in oldermen (35 years and over), and the relation between smokingand illness was almost confined to older men: amongyounger men the annual treated-injury rate was 27%higher for smokers than for non-smokers, and among7. ibid. 3rd ed., p. 624. London, 1866.8. Thorburn, W. M. Mind, 1918, 27, 345.9. Occam, Gulielmus de. Quodlibeta Septem. Tractatus de sacramento

altaris; quodlibet v, quaestio v. Strassburg; G. Husner, 1491, versoof m2.

10. Occam, William of. Summa totius logicae (edited by P. Boehner);I. 12, p. 39. New York-Louvain, 1951. (" It is vain to do with morewhat can be done with fewer.")

11. Encyclopædia Britannica, 1955, 16, 681.12. Lowe, C. R. Brit. J. prev. soc. Med. 1960, 14, 57.