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NATURE 



[June io, 1920 



eighteen. The latter are understood to have 

 justified their selection, and in the opinion of 

 some officers were superior to the Dartmouth 

 entry in certain respects. One reason for such 

 a superiority, if it really exists, is so dominant 

 that it is unnecessary to look further. The 

 "direct entry" midshipmen finished their educa- 

 tion uninterruptedly at the schools, carrying- it 

 on to the ag-e of seventeen and a half or eighteen. 

 The Dartmouth boys were sent to sea prema- 

 turely, many of them at fifteen and a half instead 

 of at the normal age of seventeen. They were an 

 unfinished product, and from an educational point 

 of view it is satisfactory that this curtailment of 

 general education should have had such a marked 

 effect on efficiency at sea that many officers were 

 led to make the comparison referred to above. 

 For the reason stated, the comparison could not 

 be fair, but it was made, and it set naval officers 

 thinkingf. 



Not so many years ago it was axiomatic in 

 the Navy that sailors "must be caug^ht young-," at 

 a tender age, and not when they leave a public 

 school. It is no long-er axiomatic. There is 

 acute division of opinion among naval officers on 

 this subject. So long as it was considered neces- 

 sary that cadets of thirteen and upwards should 

 spend one-quarter of their time in engineering, 

 it was impossible to look to the schools of the 

 country for the secondary education of naval 

 officers. But the amount of engineering to be 

 learnt in future between thirteen and eighteen is 

 not more than could be taught at any well- 

 equipped school. The problem is therefore open 

 whether the Navy is to continue to undertake 

 the secondary education of its officers, or to leave 

 the task to the schools. The P'irst Lord stated 

 that the Admiralty had no intention of abolishing 

 Dartmouth as well as Osborne, and referred to 

 advantages which could be conferred at a naval 

 college on the sons of needy naval officers. But 

 he believed the public-school system of entry- — the 

 "direct entry" system — to be thoroughly good, 

 and fifteen midshipmen are to be entered annually 

 from the schools, as against 120 through Dart- 

 mouth. 



In favour of maintaining a naval college for 

 cadets is urged the advantage of early acquaint- 

 ance with Navy habits and discipline, the doubt 

 whether the numbers required — very moderate 

 numbers now— could be recruited at the age of 

 eighteen, the present overcrowded state of the 

 public schools, and the special consideration re- 

 ferred to by Mr. Long in his speech. In favour 

 NO. 2641, VOL. 105] 



of relying entirely on the schools of the coun,try, 

 many naval officers argue that a boy's outlook is. 

 narrowed by association from so early an age 

 with none but those of his own profession ; that 

 there is nothing at a naval college which quite 

 makes up for the influence exerted by a good 

 public-school house master; that "direct entry " 

 saves heavy expense to the Exchequer; and that 

 it is more difficult to select at the age of thirteen 

 than at eighteen. 



The debate, therefore, has .begun, and the out- 

 come will probably be determined by the eventual 

 balance of opinion within the Service. 



The Ultimate Data of Physics. 



An Enquiry concerning the Principles of Natural 

 Knowledge. By Prof. A. N. Whitehead. 

 Pp. xii + 200. (Cambridge : At the University 

 Press, 1919.) Price 125. 6d. net. 



PHYSICISTS and philosophers can unite 

 unreservedly in an expression of gratitude 

 to the author of this most acute and original 

 work. At the present time, when it is gener.ally 

 recognised that the ultimate concepts of physics, 

 require reinterpretation, it is a piece of great 

 good fortune that the task should be undertaken 

 by a thinker who is not only one of the foremost 

 of living mathematicians, but also a metaphysician 

 who sees clearly the wider issues that are involved. 

 As Prof. Whitehead remarks, the incoherent 

 character of the traditional concepts of specula- 

 tive physics has long been a commonplace in philo- 

 sophical treatments of the subject. Instantaneous 

 moments, geometrical points, unextended parti- 

 cles, etc.- — these may be convenient, and even 

 essential, notions for the purposes of physical 

 investigation, but, if taken to indicate existent 

 entities, are quite unworkable notions. On such 

 a basis the fact, for example, of change in all its 

 forms would become not merely incomprehensible,, 

 but contradictory; to be intelligible, "change 

 must," as Lotze put it, "find its way into the 

 inside of being." In other words, change as mere 

 sequence, as mere alternation, is an impossible 

 thought. Change means, if it means anything,, 

 continuous modification in that which preserves a 

 certain identity or unity, without, however, imply- 

 ing that the latter ingredient is something 

 separate from the former. Nothing which is 

 characteristic of force, velocity, energy, and life 

 can exhibit itself at a durationless instant. The 

 slightest functioning of a living organism obvi- 

 ously takes time, but so also does that of a mole- 

 cule of iron. In Aristotelian language, it may be 

 asserted that the true nature of any real existent 



