102 INDUCTION. 



bited. Since life cannot exist there in the manner in 

 which it exists here, the greater the resemblance of 

 the lunar world to the terrestrial in all other respects, 

 the less reason we have to believe that it can contain 

 life. 



There are, however, other bodies in our system, 

 between which and the earth there is a much closer 

 resemblance ; which possess an atmosphere, clouds, 

 consequently water '(vi some'-lui'd analogous to it,) 

 and even give strong indications of snow in their polar 

 regions; while rfc : cold; or '-heat,' though differing 

 greatly on the average from ours, is, in some parts at 

 least of those planets, possibly not more extreme than 

 in some regions of our own which are habitable. To 

 balance these agreements, the ascertained differences 

 are chiefly in the average light and heat, velocity of 

 rotation, intensity of gravity, and similar circum- 

 stances of a secondary kind. With regard to these 

 planets, therefore, the argument of analogy gives a 

 decided preponderance in favour of their resembling 

 the earth in any of its derivative properties, such as 

 that of having inhabitants ; though, when we consider 

 how immeasurably multitudinous are those of their 

 properties which we are entirely ignorant of, compared 

 with the few which we know, we cannot attach more 

 than a very trifling weight to any considerations of 

 resemblance in which the known elements bear so 

 inconsiderable a proportion to the unknown. 



Besides the competition between analogy and 

 diversity, there may be a competition of conflicting 

 analogies. The new case may be similar in some of its 

 circumstances to cases in which the fact m exists, but 

 in others to cases in which it is known not to exist. 

 Amber has some properties in common with vegetable, 

 others with mineral products. A painting, of un- 



