GALILEO AND HIS JUDGES. 133 



before it was fitted for the reception of man on its 

 surface, or, indeed, for that of any of the higher 

 mammalia. The Earth had had a long history, and 

 had undergone vast changes, ranging perhaps over 

 many millions of years, before man appeared on the 

 scene ; and the period that has elapsed since that 

 event, whatever the date of it may be, is simply 

 nothing in comparison of the ages that had previously 

 rolled by since the first moment when the darkness 

 gave way, and the light appeared. It is, then, far 

 from unlikely that our own Earth is the only planet 

 in the solar system which at the present time is 

 suitable for the habitation of man, or creatures 

 resembling him.* 



Passing then from our own system, we come to the 

 myriads of suns, some, we may well believe, far greater 

 than our Sun, which are spread through the realms of 

 space .t Many of these we may reasonably suppose 

 are surrounded by planets, and in one or two cases 

 there are special reasons for thinking that some 

 opaque body intervenes occasionally between the star 

 and ourselves. But the conditions under which 

 several of the stars (we know not how many) exist, is 

 very different from that to which we are accustomed 

 here with our own Sun. There are double stars which 



* It is, I think, Mr. Proctor who uses this argument. in one of 

 his works, to prove how very doubtful a thing is the existence of 

 highly organised and rational beings on the other planets. 



f It is quite possible, as Mr. Lockyer has recently argued, that 

 many objects that appear to us as stars, are in reality nebulae in a 

 more or less advanced stage of condensation. 



