September eg, [918 



NATURE 



43 



the theorist-mathematician, with so much success, 

 into the physico-chemical field of science." We 

 are not sure that "theorist" is the proper title 

 for the generalising thinker like Herbert Spencer, 

 nr that Dr. Rignano sufficiently realises the 

 dangers of the synthetician's ambition, hut we 

 agree with his protest against the narrow view 

 that all experimentation must be done in a labora- 

 tory What the author really stands for is, that 

 complementary in the work of the experimentalist 

 is the work of the quiet thinker who has had 

 sufficient discipline in scientific method on 

 one hand, and in metaphysical analysis mi tin 

 other. For this function the book before us is an 

 apologia, and, while it naturally illustrates the 

 risks uf tin adventure, it also clearly demon- 

 strates its rewards. The second essay gives a 

 luminous exposition of the synthetic value of the 

 evolution-theory. "No other theory, perhaps, has 

 succeeded in bringing into one general survey so 

 many disparate phenomena, and in co-ordinating 

 in one complete complex the numerous individual 

 theories which hold their own in widely differing 

 branches of science, and which, at first sight, 

 seem to have nothing in common." We wish, 

 however, that the author had said something 

 about the fallacy so frequently involved in apply- 

 ing the same word "evolution" to historical 

 sequences which have little in common except 

 that they are processes of becoming. 



The central part of the hook is undeniably 

 difficult, but it is, as an attempt at least, of great 

 importance. It gives an outline of a mnemic 

 theory of life, which the author has previously 

 expounded in his work on "centro-epigenesis. " 

 Let us try to state the main idea without too much 

 of its special terminology. It is quite certain that 

 a relatively simple living creature without any 

 nerve-centres can somehow en register the results 

 of its experience so that subsequent actions are 

 influenced. That is a relatively simple "mnemic" 

 phenomenon. A set of cells that have taken to 

 some novel metabolic routine, such as secreting an 

 anti-body to some toxin, may keep up the habit 

 long after the original stimulus has ceased to 

 operate. That is another illustration of " mnemic " 

 phenomena. There is some sort of functional 

 inertia in individual organisms- -a tendency which 

 in its most fundamental expression is simplv to 

 persist in a given phase of moving equilibrium 

 (the word "stationary" used in the translation 

 does not suggest the right idea). Now if the 

 germinal substance is made up of "specific 

 potential elements " which act as accumulators 

 of particular modes of energy — "representative 

 currents," as it is said — it may also be that in 

 the course of the individual development of the 

 offspring there is an activation of these and an 

 irradiation from the centre outwards so that a 

 formative influence is exerted. "The substance 

 ol which each of these specific potential elements 

 is i omposed, which is capable of giving as dis- 

 charge a single well-determined specific nervous 

 current, is still one and the same substance which 

 this nervous current, when it acts as a ' charg- 

 XO. 2551. VOL. IO2] 



ing ' current, can in its turn form and deposit." 

 In this is found the explanation of the transmission 

 icquired charactet (supposing that to be a 

 fact) and of the recapitulation of phylogenetic 

 stages in ontogeny. Ii appeal to us that the 

 specific form of Dr. Rignano's theory is not in 

 grips with the facts, but to those who believe that 

 experience counts in racial evolution in some other 

 way than either Lamarck or Darwin recognised, 

 adventure in mnemic theory will be wel- 

 come. As to the nervous energy referred to, with 

 its fundamental property of specific accumulation, 

 it is said to obey the general laws of i 

 but is regarded as a monopoly of living organisms. 

 In other words, there is a specific vital energy, 

 as the late Prof. Assheton also maintained. 



Organisms strive and cry, they exhibit en- 

 deavour and initiative, they are swayed by 

 "affective tendencies." The author seeks to show 

 that these are fundamentally referable to the ten- 

 dency to maintain physiological integrity or equi- 

 librium. Inborn affectivities with a mnemic basis 

 express themselves in habitual actions, and new 

 habits form new affectivities of the most varied 

 nature. If "habit is second nature," then, in- 

 versely, "nature" is nothing but "first habit" — 

 a deliverance that would have pleased Samuel 

 Butler. The author recognises, of course, the 

 complications that are added in organisms with 

 fine brains and strong emotions, that secondary 

 affectivities may come to overrule the primary 

 ones, and so on; but all the apparent "finalism" 

 of life rests on the mnemic property of living sub- 

 stance, which is admitted to be beyond chemical 

 and physical formulation. 



We have left too little of our allotted space for 

 the remaining chapters. In answer to the am- 

 bitious question, " What is consciousness?" the 

 author maintains that a psychic state is not in 

 itself conscious or unconscious, but becomes one 

 or the other only in relation to some other psychic 

 state. As to the rdle of religion, it is argued that 

 its social functions are gradually waning away, 

 having been replaced by other influences. For the 

 individual, however, it is likely to remain, in some 

 form or other, as an expression of man's uncon- 

 querable desire to push beyond the frontiers of 

 science and in a stretching out of his hands to 

 relieve his surcharged emotion. Against the fata- 

 listic dogma of "historic materialism" which 

 exaggerates the "inevitable march " of economic 

 processes, the author argues cogently that even in 

 the recognition of the struggle between classes 

 there is on the part of extreme Marxists a welcome 

 contradiction in terms, for the agency of free men 

 with ideas and ideals is thus admitted to be a 

 factor thai counts. In spite of its exaggerations, 

 however, the fundamental idea of "historic 

 materialism " has had an important synthetic 

 function in binding together the previously discon- 

 nected disciplines of economics, law, and history. 

 I he hook ends with a dispassionate discussion of 

 Socialism and its future and with a note of hope- 

 fulness in recognising the. in part compulsory 

 and in part spontaneous, enlargement and sensi- 



