THE FUTURE. 175 



This brings us, in conclusion, to look at the earth's pro- 

 bable Future through her knowledge of her Past. As 

 students of nature, we can no more refrain from this in- 

 quiry than we can cease to take an interest in her bygone 

 history. The present is a mere evanishing point : yesterday 

 it was the future, to-morrow it will be the past. Past, pre- 

 sent, and future are but portions of one vast cycle of change ; 

 and could we determine with accuracy the rate of progress 

 in the past, the future would be rationally computable. In 

 the mean time our knowledge of world-history is far from 

 perfect, hence our estimate of the future can assume at 

 best little more than the character of speculation. Still, 

 we are fairly entitled to hold that as the rocky crust has, 

 under the operation of the physical forces, been the theatre 

 of incessant change in, the past, so it will continue to be 

 subjected to similar mutations in the future. As we see no 

 decline in the forces that operate, so reason refuses to admit 

 a cessation of their results. Volcanic energy will shift its 

 centres of activity ; continents will be submerged ; sea- 

 beds be uplifted into dry land ; climatic influences be altered ; 

 living races will succumb to obnoxious conditions; and new 

 ones will appear co-adapted to these newer phases. As in 

 the past the changes were always gradual and local, and the 

 newer phases ever bore a certain appreciable relation to 

 those that went before ; so in the future we may rely on a 

 similar gradation, and believe that the differences between 

 the phases yet to be will never exceed those geology has 

 discovered between two successive formations. 



As with the physical, so with the vital forces. Age after 

 age has been characterised by its own peculiar phases of vital- 

 ity, and as we fail to detect any symptom of decline, so we 

 may fairly presume that the future aspects of life will differ 

 from that which now prevails, as that which exists differs 

 from that which preceded. As the course has ever been to 



