6oo TEE POPULAR SCIENCE MONTHLY 



imagination, keeping within the limits of reason, we can predict the 

 rate of progress will be continuous. It is quite conceivable that before 

 this generation is passed we shall plough with power generated by the 

 tides and transmitted by wireless processes, and that radium will be 

 harnessed so that its incalculable energy can be used. With the tre- 

 mendous increase in power the surface of the earth can be enlarged 

 indefinitely. Why should not the plains of Europe and America be set 

 on edge, or why should not artificial heat and light make possible sev- 

 eral layers of productive soil, and certainly it can be employed all the 

 year round ! Already sanitation and invention are making possible the 

 exploitation of the tropics, the really productive regions of the earth 

 which hitherto have been undeveloped. Men can soon work where they 

 can not live continuously because they can commute in airships and 

 change climatic conditions daily. 



In the light of these facts and fancies let us consider the validity of 

 Malthus'"s three principles : 



1. " Population is necessarily limited by the means of subsistence." 

 This is more imaginative than dangerous, for, since " means of sub- 

 sistence " is psychological as well as physical, it can not become a 

 mathematical term. Nowadays our magazines are telling us that con- 

 sumption of one half or one third of the " means of subsistence " would 

 add greatly to our efficiency. I myself have made a definite reduction 

 in the amount of food consumed and thereby multiplied my efficiency. 

 Furthermore, it is undoubted that the science of nutrition is going to 

 add many units to the food supply by subtracting the injurious, the 

 wasted, and the unnecessary. This is the prospect before us, but in the 

 meantime, with all the natural forces for multiplication of population 

 active, nevertheless the means of subsistence has increased far beyond 

 any proportions that have before prevailed. There is not the slightest 

 evidence to-day that means of subsistence is directly effecting the in- 

 crease in population. 



2. " Population invariably increases where the means of subsistence 

 increases, unless prevented by very powerful and obvious checks." This 

 is so untrue to-day that it is not open to argument. In fact, the por- 

 tion of population having the greatest means of subsistence is standing 

 still while the poorest furnishes the greatest increase. To be sure, the 

 standard of life may be the line at which the force of the means of sub- 

 sistence is defined, but this is an artificial line. The rate of increase is 

 not lessened by any powerful and obvious check, and it is not beginning 

 to keep up with the rate of increase of the means of subsistence. There 

 never was a time when the world was as well fed as at the present. 



3. " These checks and the checks which repress the superior power 

 of population and keep its effects on a level with the means of subsist- 

 ence are all resolvable into moral restraint, vice and misery." Professor 



