156 



SCIENCE. 



[Vol. XXI. No. 529 



at other times, when the wave of public confidence is high and 

 strons;. such a failure has no perceptible etfect beyond those im- 

 mediately concerned. To predict the time of the next panic it 

 would bs necessary first to determine the periodic laws of specu- 

 lative eras, expansion and contraction of the currency, over pro- 

 duction, and other principal causes, and then combine them to 

 find when like phases coincide. Just as two rays of light of op- 

 posite phases may by interference annihilate each other, so two 

 social movements or tendencies, both of great power and effect, 

 may, when they enter as terms in the. formula of another move- 

 ment, cancel each other by reason of their opposite signs or 

 phases. On the contrary, all of the greatest movements of the 

 social world, such as the founding and spread of Christianity, 

 the fall of Rome, the Reformation, the colonization of Aaierica, 

 and the French Revolution, have been the result of the synchro- 

 nous combinations of many causes or terms of the same sign and 

 phase, so that the sum of the whole — even if we neglect the in- 

 finite number of small terms — is one of transcendent magni- 

 tude. 



The great advantage of the philosophical study of history is 

 that by this method the constituent elements of events and the 

 movements to which they belong are made apparent, and for this 

 purpose we must be provided with the data for expressing the 

 trend and phase of all the political, philosophical, and religious 

 movements to which they are related. The complexity of the 

 problems involved is indicated by the fact that different scholars 

 ai'rive at such contradictory conclusions. Nevertheless, it is be- 

 lieved that this modern method of investigation will revolutionize 

 all the social sciences as it has already revolutionized political 

 economj', and that after the method has been more systematically 

 applied to modern statistics, and the number of terms considered 

 has been increased, the conclusions or results reached by different 

 authorities will be less and less discrepant, and that thus we may 

 hope ultimately to reach a certainty and precision, in the social 

 and metaphysical sciences, which will be comparable to the pre- 

 cision of physical data. If we throw a pebble into the air we can 

 express mathematically the motion of the earth toward the peb- 

 ble as well as the motion of the pebble toward the earth, and we 

 might perhaps express in a similar way the effect which the re- 

 pair of a roof in San Francisco would have upon the prices of 

 building materials in New York, and vice versa. More than this, 

 is it not possible that a new psychology will be able to weigh 

 and measure the volitions, tastes, and emotions of the mind, so 

 that this science as well as history and political economy may 

 become partly quantitative ? 



The methods of mathematics can be applied to the metaphysi- 

 cal sciences more extensively than has been done heretofore. 

 These methods have already been applied, in a limited way, to 

 all subjects having much statistical data, also to logic. Indeed, 

 mathematical forms and analysis may be used in any science, as 

 chemistry, which is subject to quantitative treatment The 

 qualitative analysis must always precede the quantitative analysis 

 in any science, but most subjects are now so fully developed that 

 it is time for original research to be directed to the quantitative 

 treatment. This is being done in a kind of tentative way at sev- 

 eral universities, and it is believed that the comparative, quanti- 

 tative method of investigation will be as useful in other sciences 

 as it has already proved to be in political economy and phi- 

 lology. 



NATURAL SELECTION AND USE-INHERITANCE. 



BY VICTOR TARROS, BOSTON, MASS. 



Evolutionists will be extremely gratified to learn that Mr. 

 Spencer has resumed the discussion of the subject of the factors 

 of organic evolution. Since the publication, several years ago, 

 of Mr. Spencer's controversial essays on this subject, the so-called 

 pure-Darwinians have practically enjoyed a monopoly of the field ; 

 and some of the more rash biologists have even allowed themselves 

 to advance the claim that the use inheritance hypothesis was 

 utterly discredited. Mr. Spencer's unsatisfactory state of health, 

 it was understood, necessitated his neglect of this and many 

 other '• unsettled problems" and the concentration of his atten- 



tion, on ethical questions, — the part of his synthetic philosophy 

 rightly regarded by all as the crown of the whole. Students of 

 evolution were anxious to hear " the other side," the answers to 

 the formidable objections of Professor Weissman au't his disci- 

 ples or co-believers, and the announcement of Dr Romanes's 

 " Darwin and After Darwin," a part of which work was to treat 

 elaborately the question of the number and relative importance 

 of the factors of organic evolution, was received with gi-eat 

 pleasure. But no one realizes more keenly the transcendent im- 

 portance of the question of the inheritance of acquired characteis 

 than Mr. Spencer, and he is to be congratulated upon the kind- 

 ness of fortune that has enabled him to spare some lime and en- 

 ergy to the further consideration of the subject, use-inheritance 

 vs. sexual selection. It will conduce to firmness of grasp and 

 clearness of understanding to quote here certain passages from 

 Mr. Spencer's preface to his " Factors of Organic Evolution." 



'•Though mental phenomena of many kinds," wrote Mr. Spen-' 

 cer, "and especially of the simpler kinds, are explicable only as 

 resulting from the natural selection of favorable variations; yet 

 there are, I believe, still more numerous mental phenomena, in- 

 cluding all those of any considerable complexity, which cannot 

 be explained otherwise than as results of the inheritance of func- 

 tionally-produced modifications. What theory of psychological 

 evolution is espoused, thus depends on acceptance or rejection of 

 the doctrine that not only in the individual, but in the successions 

 of individuals, use and disuse of parts produce respectively in- 

 crease and decrease of them. 



" Of course there are involved the conceptions we form of the 

 genesis and nature of our higher emotions; and, by implication, 

 the conceptions we form of our moral intuitions. If function- 

 ally-produced modifications are inheritable, then the mental asso- 

 ciations habitually produced in individuals by experiences of the 

 relations between actions and their consequences, pleasurable or 

 painful, may, in the successions of individuals, generate innate 

 tendencies to like or dislike such actions. But, if not, the gene- 

 sis of such tendencies is, as we shall see, not satisfactorily ex- 

 plicable. 



"That our sociological beliefs must also be profoundly affected 

 by the conclusions we draw on this point, is obvious. If a nation 

 is modified en masse by transmission of the effects produced on 

 the natures of its members by those modes of daily activity which 

 its institutions and circumstances involve, then we must infer 

 that such institutions and circumstances mould its members far 

 more rapidly and comprehensively than they do if the sole cause 

 of adaptation to them is the more frequent survival of individuals 

 who happen to have varied in favorable ways." 



The above expresses Mr, Spencer's view of the profound im- 

 portance of the indirect bearings of the purely biological argu- 

 ment upon the factors of organic evolution. Now that we have 

 refreshed our memory on this point, let us proceed to give a brief 

 but careful summary of Mr. Spencer's latest contribution to the 

 controversy, to be found in an article, entitled "On the Inade- 

 quacy of Natural Selection," in the Coniemxiorary Review for 

 February. We preserve as far as possible Mr. Spencer's style. 



Students of psychology are familiar with the experiments of 

 Weber on the sense of touch. He found that different parts of 

 the surface differ wilely in their ability to give information con- 

 cerning the tilings touched. By actual measurements he showed 

 that tlie end of the forefinger has thirty times the tactual dis- 

 criminaliveness which the middle of the back has Between 

 these extremes there are gradations. The inner surfaces of the 

 second joints of the finger can distinguish separateness of posi- 

 tions only half as well as the tip of the forefinger. The innermost 

 joints are still less discriminating, their power being equal to that 

 of the tip of the nose. The palm of the hand and the cheek have 

 alike one fifth of the perceptiveness which the tip of the fore- 

 finger has, and the lower part of the forehead has one-half of that 

 possessed by the cheek. The crown of the head is far less dis- 

 criminating, and the breast still less. 



What is the meaning of these differences? How, in the course 

 of evolution, have they been established? If "natural selection" 

 or survival of the fittest is the assigned cause, then it is required 

 to show in what way each of these degrees of endowment has 



