644 



NATURE 



[November 3, 1923 



arc currtlaicu v. 

 savs wc mav h 



l)ut MMiittlim^ 

 lite an jiitc;,'ral 



' in a 



- Mf 



lia\ r 



wiitfi > n 



111- , .11 1 ! 



<< analysis nl n l.iud- 

 i „. ^ ..;;..; .l;,..,:.l. . is dilTunl! 1 iccuuse 



IS a correlate of m s at a 



very udvaiux'd stage of its cM/iiii, 'ngress, 



" rc(]uiriiii,' the effective liw ul Htc ,i :((|uircs 



the pninary go of ])li\>ir,il lAiiU^, . . . linked with 

 cnuT^ent (]ualities at si> lii:Ji a lc\tl. and iiudhiiiL; so 

 many kinds ol' rehiudiu^s ot lower order>." There 

 follows an al'le discns^ion of reference lielow the level 

 of relleeii\e consciousness, from which Prof. Lloyd 

 Morgan proceeds to his view of " projicience," per- 

 ceptual reference to a distance (Sherrington), reference 

 of all objective characters to things at a distance 

 (Lloyd Morgan). Projicience, he says, begins '" when 

 mind or consciousness is supervenient in the course of 

 evolutionary progress, and takes definite form only 

 when distance-receptors are differeiri lUil on the plane 

 of life. It presupposes the evolution of mind as an 

 emergent quality of the psychical system correlated 

 with the physical system of the organism." Mind is 

 emergent in evolutionary history. When it comes, 

 the " particular go " of events at the level of its advent 

 is altered. This is so with all emergents. " So long 

 as the words are used in a purely naturalistic sense, 

 one may say that the higher kinds of relatedness guide 

 or control the go of lower-level events." — We are not 

 sure that that is not rather a dangerous sentence. 

 What is the naturalistic sense of " guiding " and 

 " controlling " ? The question comes back to us in 

 reading the chapter on causation and causality, where 

 Prof. Lloyd Morgan is under some difficulty to rescue 

 the concept of causation (or rather " causality " as 

 better adapted to his theistic position as we understand 

 it) from the clutches of Mach and Bertrand Russell, 

 who both desire the extrusion of the word " cause " 

 from the philosophical vocabulary. 



We have neglected the author's theism for the 

 exposition of his naturalism because he himself regards 

 the former as " supplementary." It is to be hoped 

 that impatience with the crudity of much in current 

 biological literature has not closed our eyes to opposite 

 excess in Prof. Lloyd Morgan's work, which, rightly 

 understood, affords encouragement for the rehabilita- 

 tion of biology on strictly naturalistic lines. 



Tudor Jones. 

 NO. 2818, VOL. 1 12] 



Mathematical Astronomy. 



ranrs. 



pa 



no 



Ir. 



Wil 



'allUtCtUlu 



■ Aufla^e. 



lehn l'.ni.'elinann, n>22.; 



cr. 



■ \-> et 



fondue. 



(tid der 



lUf. 



■)'j : 



(11 



iii'jcfl of <(l(-,iial mechanics is dis- 



'WO 



and tlif 



centuries it iia> \nvu tia- oii 

 of the mo.it eininint in.ti :, .._,..„,, v. 



l)()th in the fonii lical studies 



and of the most extensive praeiical calculations ever 

 undertaken, is vast. For the most y)art the memoirs 

 naturalK' ]ircvii|)|)o.>(_' a [jcmral iaii.iliarit \- will) 

 established n- lul arc concerned with special 



phases of tlit They will always leave room 



for the treatise ainiinu at a iiioic introductory and 

 systematic exposition. It may appear that in a field 

 so intensively cultivated certain classical lines would 

 have become firmly established, to the exclusion of 

 any fresh and original treatment ; that the possibilities 

 open to the writer of a new treatise would have been 

 largely exhausted. That would be to unden'alue the 

 richness of the field completely. We are certainly 

 fortunate in the possession of se\cral such systematic 

 treatises, of the higlicst quality. But when they are 

 brought together, in all ki— ■ > ■<, they make no 

 excessive number. It is pi afe to assert that 



no other branch of science is so completely free from 

 superfluous works of this kind. Xor is the reason far 

 to seek. There is no mercenary incentive to their 

 production, and the only motive must be allied with 

 sincerity of purpose. 



\\ hen therefore Prof. Andoycr modestly refers in 

 his preface to the rashness of his undertaking after the 

 works of Tisserand and Poincare, he need not be taken 

 seriously at all. Tisserand s is a most beautiful work 

 of exposition, original rather in form than in matter. 

 Poincare's " Methodes nouvelles " is a work of 

 original genius, which left its autlior still free to find 

 independent field.s for his " Lemons." The very- 

 distance which separates these works in scope and 

 manner would make it strange if they had exhausted 



the possibilities of the subject for systemati * 



ment, and it is not true. It is indeed most elu 



