SCIENTIFIC USE OF THE IMAGINATION. 135 



c transport the conception of life's origin to an indefi- 

 nitely distant past.' 



Those who hold the doctrine of Evolution are by no 

 means ignorant of the uncertainty of their data, and 

 they only yield to it a provisional assent. They regard 

 the nebular hypothesis as probable, and, in the utter 

 absence of any evidence to prove the act illegal, they 

 extend the method of nature from the present into the 

 past. Here the observed uniformity of nature is their 

 only guide. Within the long range of physical enquiry, 

 they have never discerned in nature the insertion of 

 caprice. Throughout this range, the laws of physical 

 and intellectual continuity have run side by side. 

 Having thus determined the elements of their curve in 

 a world of observation and experiment, they prolong 

 that curve into an antecedent world, and accept as 

 probable the unbroken sequence of development from 

 the nebula to the present time. You never hear the 

 really philosophical defenders of the doctrine of Uni- 

 formity speaking of impossibilities in nature. They 

 never say, what they are constantly charged with 

 saying, that it is impossible for the Builder of the 

 universe to alter His work. Their business is not with 

 the possible, but the actual not with a world which. 

 might be, but with a world that is. Tms they explore 

 with a courage not unmixed with reverence, and 

 according to methods which, like the quality of a tree, 

 are tested by their fruits. ..They have but one desire 

 to know the truth. They have but one fear to 

 believe a lie. And if they know the strength of science, 

 and rely upon it with unswerving trust, they also know 

 the limits beyond which science ceases to be strong. 

 They best know that questions offer themselves to 

 thought, which science, as now prosecuted, has not even 

 the tendency to solve. They have as little fellowship 



