382 PART V. WORKING STAGE. 



paid to the more intimate aspects of life. Otherwise, the truth 

 we have attained to is only a partial one and arbitrary to boot. 

 In all the sociological sciences the connection between theoretical 

 and practical deduction is so close that in any sociological in- 

 vestigation purporting to be comprehensive it would argue a 

 grave dereliction of scientific duty to pass cavalier-like over 

 what are called practical problems. Given that the deductive 

 enquiry is virtually completed on the theoretical side, it should 

 automatically open on the practical side. Thus the statistician, 

 the economist, the jurist, the historian, the philologist, the 

 psychologist, the anthropologist, the ethnologist, the educationist, 

 the moralist, the religious and aesthetic thinker, should conceive 

 it as part and parcel of their duty to begin with precisely de- 

 fining their task, proceed to observation, generalisation, verifica- 

 tion, interim definition, and deduction, and pass beyond to applica- 

 tion. In reality, as Conclusion 2 implies, the problem of drawing 

 practical deductions should be a living one for the inquirer from 

 the introductory to the terminal stages of his investigation, 

 especially now that the facts of the practical life have been 

 classified to a notable extent and that the life of practice is 

 becoming more and more organised and organisable. 



The biological and physical sciences occupy an analogous 

 position. The varied problems of agriculture, frugiculture, horti- 

 culture, arboriculture, dairy farming, stock rearing, and fisheries ; 

 of hygiene (general, industrial, school, etc.), dietetics, appro- 

 priate clothing, and sanitation; of the combating of infectious 

 and other diseases ; and of insect pests, dangerous animals, and 

 premature old age and reckless living, should be ever pressing 

 for solution in the mind of the biologist. The physicist and 

 chemist have similar tasks before them the physicist's rays, 

 compass, and knowledge of mechanics, for instance, are of in- 

 calculable import, and so are his discoveries of novel or im- 

 proved material energies and raw materials, or his contributions 

 to the ventilation, lighting, heating, acoustics, cleaning, health, 

 design, safety, and soundness of every type of building and 

 boat, whilst the chemist's contributions in regard to manufac- 

 tures, agriculture, and medicine are invaluable. The meteo- 

 rologist may also help mankind to produce and avert, or at 

 least predict, rainfall, atmospheric humidity, heat, stronger or 

 weaker air currents, and clouds, whilst the astronomer, the 

 geographer, the geologist, the mineralogist, the seismologist, the 

 oceanographer, and all other types of scientists not least the 

 mathematician may equally render priceless service by ex- 

 tending and systematising the realm of practical truth. 



For instance, psychologists and physiologists have been for a 

 generation engaged in inventions of a practical character relating 

 to industry. The energy expended in a particular task has been 

 examined by means of the dynamometer, the fatigue experienced 

 by the ergograph, the pain felt by the algesimeter, the vital 



