INHABITED WORLDS. 269 



middle period as that to whicli the wliole geologi- 

 cal history of our own earth bears witness, from 

 the dawn of life to the present day. It would be 

 rash to assert that during such an intermediate 

 age every planet does actually prove the theatre 

 of life of some sort ; all that we are entitled 

 legitimately to assert is merely this, that under 

 such and such conditions, and under no others, 

 life becomes at any rate possible. 



This consideration shows us at once how foolish 

 are the ordinary hasty speculations of thoughtless 

 reasoners as to the possibility or probability of 

 "other worlds than ours" being really inhabited. 

 When such people say " inhabited," they mean in 

 effect, though they do not say so, inhabited by 

 human beings. like ourselves, or at least by other 

 and similar rational creatures. But the real point 

 to be settled first is a far more fundamental one ; 

 it is the prior question whether life in au)^ form, 

 animal or vegetable, or anything resembling it, is 

 there possible. For man presupposes beef and 

 mutton, wheat and potatoes, or something at any 

 rate very like them. How narrow and illogical 

 it is to concentrate our attention solely on the 

 probability or improbability of there being men 

 and women in Mercury or Venus, while we never 

 think of inquiring whether there are lions or 

 tigers there, oak-trees or chestnuts ! And that, 

 again, leads up naturuHy to tlie further conclusion 



