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remain behind ; we know not how few. It would be presumptuous indeed 
to assume in any case that we had already reached the last link, and to charge 
with irreverence a fellow- worker who had attempted to push his investigations 
yet one step further back. On the other hand, if a thick darkness enshrouds 
all beyond, we have no right to assume it to be impossible that we should 
have reached even the last link of the chain, a stage where further progress 
is unattainable ; and we can only refer to the highest law at which we 
stopped to the fiat of an Almighty Power. To assume the contrary as a 
matter of necessity, is practically to remove the First Cause of All to an 
infinite distance from us. The boundary, however, between what is clearly 
known and what is veiled in impenetrable darkness is not ordinarily thus 
sharply defined. Between the two there lies a misty region, in which loom 
the ill-discerned forms of links of the chain which are yet beyond us : but 
the general principle is not affected thereby. Let us fearlessly trace the 
dependence of link on link as far as it may be given us to trace it, but let us 
take heed that in thus studying second causes we forget not the First Cause, 
nor shut our eyes to the wonderful proofs of design which, in the study of 
organized beings especially, meet us at every turn.” 
