46 



SCIENCE. 



[Vol. VIII., No. 180 



it in so simple an operation as the extraction of a 

 tooth ; and a jury would be doing its full duty in 

 holding responsible for the death of the patient 

 any physician or dentist who administered it in 

 such a case, with a fatal result. 



One of the difficult problems which pre- 

 sents itself for solution in the south is how to 

 reduce the mortality among the blacks. That it 

 has not yet been solved is made evident by a study 

 of the vital statistics of southern cities. These 

 records show that the death-rate of the negroes is 

 double that of the whites. Savannah, Ga., how- 

 ever, seems to be exceptionally unhealthy in this 

 regard. It is stated that in that city, while the 

 rate for the white population is but 12.19 per 

 thousand, a remarkably low rate and probably 

 not correct, that for the blacks is 122. If these 

 figui-es are correct, there is opportunity for much 

 missionary work of a sanitary nature in the city 

 of Savannah, 



ECONOMIC LAWS AND METHODS. 



If it should be said that the material out of 

 which the science of mechanics was built was 

 wood and stone, iron and steel, every one would 

 see the mistake. But when Mr. H. C. Adams, in 

 his interesting paper on economics and jurispru- 

 dence, speaks of the material surroundings of men 

 and the legal structure of society as material out 

 of which the science of economics is built, he 

 falls into precisely the same error {Science, July 2). 



It would be unfair to Mr. Adams personally to 

 lay too much stress on a random expression torn 

 from its context ; but it is not unfair to the school 

 of thought to which he belongs. We have singled 

 this expression out for criticism because it is char- 

 acteristic of the school. It represents a view of 

 the whole subject which is likely to lead to grave 

 mistakes in thinking and in action. That Mr. 

 Adams himself will make those mistakes, we do 

 not believe. We should be sorry to say a word 

 which should even seem to detract from the value 

 of his work. He is one of the few men who com- 

 bine originality with critical judgment. But the 

 high character of the writer makes it all the more 

 necessary to protest against his mistakes, even 

 though they be but incidental. What he does 

 inadvertently, others will be led to do deliber- 

 ately. 



The error lies in confounding the material to 

 which a science is applied, with the material out 

 of which it is built ; or — to put the same thing in 

 another form — in identifying the material of a 



science with the materials of an art. In itself this 

 may seem a trivial matter ; in its consequences it 

 is extremely serious. 



The material out of which the science of me- 

 chanics is built is not wood or iron, in any sense 

 whatever. The science is built out of a few sim- 

 ple laws of motion, nowhere exactly realized in 

 nature, and yet now admitted by every sensible 

 man to be true. And in like manner the material 

 out of which the science of economics is built 

 consists of a few simple laws of human nature, 

 the chief of which is that men strive to obtain 

 the maximum of satisfaction with the minimum 

 of sacrifice. It does not insist that the sacrifice 

 shall be solely physical, or the satisfaction purely 

 material. It makes no more unwarranted assump- 

 tions than does pure mechanics. The ' economic 

 man ' has as much and as little real existence as 

 the ' material point.' As the fundamental assump- 

 tions of mechanics are involved in the definition 

 of motion and the fact of its measurement, so the 

 fundamental assumptions of political economy are 

 involved in the definition of motives, and the fact 

 of their measurement. This measurement is far 

 less accurate in moral science than in physical 

 science : the danger of dogmatism is therefore 

 greater, and the need for verification more con- 

 stant. But to say that the verification is the sci- 

 ence, is as much a mistake in the one case as in 

 the other. 



It is a mistake which is often made, and which 

 does great harm, both in science and in practice. 

 It defeats the usefulness of verification as a means 

 of discovery. An illustration will help to make 

 this clear. The discovery of Neptune was due to 

 a study of the motions of Uranus. It was found 

 that these motions were not exactly such as the 

 laws of mechanics, applied to the position of the 

 known planets, would explain. It was therefore 

 assumed that there must be certain unknown con- 

 ditions which entered into the case ; and careful 

 reasoning led to the discovery of a new planet, 

 whose position and size fulfilled those conditions. 



Now, let it be observed, that, by the method 

 which the historical school so highly commends, 

 the inference from the motions of Uranus would 

 simply have been that the law of gravitation was 

 not as rigid as is commonly supposed. Such an 

 inference would not merely have been wrong in 

 itself, but it would have prevented the discovery 

 of Neptune. 



It is only when you assume a rigid law that your 

 verification leads to new discoveries ; and it leads 

 to the most fruitful discoveries where the law at 

 first seems to fail. That these new discoveries 

 may sometimes take such a form that the old state- 

 ment of the law will need to be partly or wholly 



