77 



serve, that the water is rising slowly, by a succession 

 of apparently spontaneous impulses. Since I have 

 been standing here, the water has arisen some four 

 or five feet. Now, it is clear, that this water may 

 arise to any height, if it be confined above, by a wall, 

 as it is below. It is manifestly gratuitous, for any one 

 to assume a limit to the ascension of this water. It 

 has been ascending, during the whole time I have been 

 standing here, and the presumption is, in default of 

 proof to the contrary, that it ever will continue so to 

 rise. • Now, the formation of the whole river, may be 

 clearly demonstrated by analogy with this lock. It is 

 fair to assume that, in the river, also, there exist, and 

 have ever existed, spontaneous impulses of water, 

 similar to what we here observe. Given, then, those 

 ascending, spontaneous impulses, the formation, in the 

 past, of this river, becomes clear. 



To the response of the lock-master, that Darwin 

 evidently does not understand the reason, or the cause, 

 why the water so ascends in the lock, he rejoins, that 

 there is the fact — that suffices for him — and that an 

 inquiry into efficient causes is metaphysical. The 

 lock-master explains, that the water has previously 

 fallen below the level of the river above, that it is now 

 returning to that level, and that his theory of the un- 

 limited ascent of the water, is all wrong, for the limit 

 will be reached when the water reaches the plane of 

 the river above. 



Darwin recognizes the truth of such explanation, 

 but declares that that is but pushing the difficulty 

 farther back in time ; for, how account for these origi- 



