5o6 



NA TURE 



[September 21, 1893 



a powerful advocate of iheir adequacy to bring about the evolu- 

 tion of the entire organic world, even including man up to a 

 certain stage, believes that the cosmic forces are insufficient 

 to account for the development of man in his civilised 

 capacity. "Natural selection," he writes, "could only have 

 endowed savage man with a brain a few degrees superior to 

 that of an ape, whereas he actually possesses one very little 

 inferior to that of a philosopher." Thisdeficiency in the organic 

 forces of nature he essays to supply by calling in the guiding 

 influence of a "superior intelligence." In defending this 

 hypothesis from hostile criticism he explains that by "superior 

 intelligence" he means some intrlligence higher than the 

 " modern cultivated mind," something intermediate between it 

 and Deity. But as this is a pure supposition, unsupported by 

 any evidence, and merely a matter of personal belief, it is un- 

 necessary to discuss it further. I would just, en passant, ask 

 Mr. Wallace why he dispenses with this " higher intelligence " 

 in the early stages of man's evolution, and finds its assistance 

 only requisite to give the final touches to humanity. 



In dealing with tlie detailed objections raised by Mr. Wal- 

 lace against the theory of natural selection as applied to man, 

 we are, however, strictly within the sphere of legitimate argu- 

 ment ; and evolutionists are fairly called upon to meet them. 

 As his own theory is founded on the supposed failure of 

 natural selection to explain certain specified peculiarities in the 

 life of man, it is clear that if these difficulties can be removed, 

 caiiit qiuvstio. It is only one of his objections, however, that 

 comes within the scope of my present inquiry, viz. that which 

 is founded on the supposed "surplusage" of brain power in 

 savage and prehistoric races. 



In comparing the brains of the anthropoid apes and man Mr. 

 Wallace adopts the following numbers to represent their propor- 

 tional average capacities, viz. anthropoid apes 10, savages 26, 

 and civilised man 32 — numbers to which there can be no objec- 

 tion, as they are based on data sufficiently accurate for the 

 requirements of this discussion. In commenting on the mental 

 ability displayed in actual life by the recipients of these various 

 brains, he states that savage man has "in an undeveloped state 

 faculties which he never requires to use," and that his brain is 

 much beyond his actual requirements in daily life. He con- 

 cludes his argument thus: — "We see, then, that whether 

 we compare the savage with the higher developments of 

 man, or with the brutes around him, we are alike driven 

 to the conclusion that in his large and well-developed 

 brain he possesses an organ quite disproportionate to his 

 actual requirements — an organ that seems prepared in advance, 

 only to be fully utilised as he progresses in civilisation. 

 A brain one half larger than that of the gorilla would, ac- 

 cording to the evidence before us, fully have sufficed for the 

 limited mental development of the savage ; and we must there- 

 fore admit that the large brain he actually possesses could never 

 have been solely developed by any of those laws of evolution 

 whose essence is that they lead to a degree of organisation 

 exactly proportionate to the wants of each species, never be- 

 yond those wants ; that no preparation can be made for the 

 future development of the race ; that one' part of the body can 

 never increase in size or complexity, except in strict co-ordina- 

 tion to the pressing wants of the whole. The brain of pre- 

 historic and of savage man seems to me to prove the existence 

 of some power distinct from that which has guided the de- 

 velopment of the lower animals through their ever-varying 

 forms of being." ("Natural Selection," &c. 1891, p. 193.) 



With regard to the closing sentence of the above quotation, 

 let me observe that the cosmic forces, under which the lower 

 animals have been produced by means of natural selection, do 

 not disclose, either in their individual or collective capacity, any 

 guiding power in the sense of a sentient influence, and I be- 

 lieve that the "distinct power "which the author summons to 

 his aid, apparently from the " vasty deep," to account for the 

 higher development of humanity is nothing more than the 

 gradually acquired product of the reasoning faculties them- 

 selves. Not that, for this rea.son, it is to be reckoned less 

 genuine and less powerful in its operations than if it had 

 emanated from an outside source. The reasoning power dis- 

 played by man is virtually a higher intelligence, and, ever since 

 its appearance on the field of organic life, it has, to a certain 

 extent, superseded the laws of natural selection. Physical 

 science has made us acquainted with the fact that two or three 

 simple bodies will sometimes combine chemically so as to 

 produce a new substance, having properties totally different from 



NO. 1247, VOL. 48] 



those of either constituents in a slate of disunion. Somethioj 

 analogous to this has taken place in the development of man' 

 capacity for reasoning by induction. Its primary elements, whici 

 are also those ofnatural selection, are conscious sensation, heredity 

 and a few other properties of organic matter, elements whicI 

 are common, in a more or less degree, to all living things. A 

 soon as the sequence of natural phenomena attracted the at 

 tention of man, and his intelligence reached the stage of con 

 secutive reasoning on the invariableness of certain effects fror 

 given causes, this new power came into existence ; and its opera 

 tions are, apparently, so different from those of its componen 

 elements that they can hardly be recognised as the off^pring t 

 natural forces at all. Its application to the adjustment of h' 

 physical environments has ever since been one of the m 

 powerful factors, not only in the development of humanity, b 

 in altering the conditions and life-functions of many membei 

 of the animal and vegetable kingdoms. 



I have already pointed out that the brain can no longer b 

 regarded as a single organ, but rather as a series of organs cor 

 nected by bonds of union — like so many departments in 

 Government office in telephonic communication — all, howevei 

 performing special and separate (unctions. When, therefor( 

 we attempt to lompare the brain capacity of one animal wii 

 that of another, with the view of ascertaining the quality ( 

 their respective mental manifetations, we must first deterinin 

 what are the exact homologous parts that are comparable. T 

 draw any such inference from a comparison of two brains, b 

 simply weighing or measuring the whole mass of each, woul 

 be manifestly of no scientific value. For example, in the brai 

 of a savage the portion representing highly skilled raotc 

 energies might be very much larger, while the portion represrni 

 ing logical power might be smaller, than the correspondin 

 parts in the brain of a philosopher. But should these ir 

 equalities of development be such as to balance each other, ih 

 weight of the twoorgans would be equal. In this case what coul 

 be ihe value of any inference as to the character of their menu 

 endowments? Equal-sized br.iins do not display equivalem 

 nor indeed analogous, results. To postulate such a doctrine woul 

 be as irrational as to maintain that the walking capacities ( 

 different persons are directly proportional to the weight of thei 

 bodies. Similar remarks are equally applicable to the skul 

 of prehistoric races, as it would appear that evolution had don 

 the major part of its work in brain development long bclui 

 the days of neolithic civilisation. Huxley's well-known (If 

 scription of the Engis skull — " a fair average skull, which uiigt 

 have belonged to a philosopher, or might have contained ih 

 thoughtless brains of a savage" — goes far to settle the quesiioi 

 from its anatomical point of view. Until localisation of biai 

 functions makes greater progress it is, therefore, futile tospeci 

 late to any great extent on the relative sizes of the skuUs < 

 different races either in present or prehistoric times. 



But there is another aspect of the question which militate 

 against Mr. Wallace's hypothesis, viz. the probability th: 

 many of the present tribes of savages are, in point of civiliss 

 tion, in a more degenerate condition than their forefathers wh 

 acquired originally higher mental qualities under natural selec 

 tion. There must surely be some foundation of truth in ih 

 widely-spread tradition of the fall of man. And, if such b 

 the case, we naturally expect to find some stray races with in 

 herited brains of greater capacity than their needs, in mote d( 

 generate circumstances, may require. An exact equivalent t 

 this may be seen in the feeble intellectuality of many of th 

 oeasants and lower classes among the civilised nations of modcr 

 times. Yet a youth born of such parents, if educated, ofte 

 becomes a distinguished philosopher. It is well known that 

 an organ ceases to perform its functional work it has a ler 

 dency to deteriorate and ultimately to disappear altogeibei 

 But from experience we know that it takes a long time lor ih 

 effects of disuse to become manifest. It is this persistency tha 

 accounts for a number of rudimentary organs, still to be me 

 with in the human body, whose functional activity could onl 

 have been exercised ages before man became differentiated frot 

 the lower animals. Such facts give some support to the s»g 

 gestion, previously made, that philosophy, as such, has 11 

 specially localised portion in the brain. Its function is merel 

 to direct the current of mental forces already existing. 



But, again, Mr.Wallace'sargumentinvolvestheassumptioniM 

 the unnecessarily large brain of the savage had been constructed 

 teleological principles for the sole purpose of philosophising, 

 opinion is that the greater portion of this so-called suiplii.-a»;>-' 



