THE LAW OF INCREASE. l6l 



and the earliest possibilities of material civi- 

 lization would arise. 



Now what are the changes of external cir- 

 cumstance which first, in the natural course 

 of things, w^ould bring an adverse influence to 

 bear upon Mankind ? Here again we are on 

 firm ground, because we know one great 

 cause which has been always operating, and 

 we know its natural and inevitable effects. 

 This cause is simply the law of increase. It 

 is the consequence of that law that popula- 

 tion is always pressing upon the limits of 

 subsistence. Hence the necessity of migra- 

 tions, and the force which has propelled suc- 

 cessive generations of men farther and farther, 

 in ever-widening circles round the original 

 centre or centres of their birth. Then, as it 

 M 



