XI 



great and all-encompassing, fertile for tlie future development of 

 science, it is the Permanence of Forces. No one molecule of matter 

 can be destroyed, but neither can a minimum of Energy. Thus runs 

 the important hypothesis which may come to be the soul of natural 

 science. The forces change and join, they appear under different 

 forms, but no force is annihilated. Determinate quantities of move- 

 ment, heat, light, electricity, magnetism, and nervous force respond 

 to each other, and can pass from one into the other." " There is 

 therefore a sum of energy, just as much as there is a sum of matter ; 

 both are proportionate to each other, both remain always the same." 



And Donders was hardly less prescient as he stood on the 

 threshold of that other great achievement of our era, the doctrine of 

 the Evolution of Organisms on our planet. The knowledge of the 

 elements and of the elemental forces, then rapidly extending, was 

 being more and more applied to the elucidation of certain vital 

 problems, on which the greatest minds had long speculated in vain. 

 Standing as we now do in the fuller light of those crowning dis- 

 closures of the progression of living nature through past ages which 

 we owe chiefly to the genius of Darwin and of Wallace, dealing with 

 an opulence of new materials for thought, it is very interesting to 

 notice how Donders, in that nascent period, regarded this momentous 

 subject. Already, in 1846,* he had briefly contested the then all 

 but universally accepted teleological notion of the origination of 

 organic forms by separate creative interpositions, accounting it to be 

 arbitrary and unscientific ; and soon after, on being called to the 

 Professoriate of the University, he deemed the topic " weighty enough 

 for a wider treatment, and because of its general bearing, well suited 

 to an inaugural discourse. "f Herein, after passing in review the 

 grander features of the material universe and of the earth, as then 

 known, he strives to show that the harmony everywhere pervading 

 living nature, then usually explained by the principle of design 

 {conformity to an end), is simply a necessary result of the condi- 

 tions under which all organisms have come to be what they have 

 been, or are. Though by no means denying the existence of a purpose 

 in the phenomena of nature, he insists that a doctrine of the purpose 

 can never become science, and can indeed only tend to obstruct the 

 progress of science by lulling to sleep the spirit of enquiry into the 

 laws governing the phenomena. These remain open to investigation 

 in the field of life, just as in that of inanimate matter. 



It is remarkable how firmly Donders here grasps the certainty 

 that all life has been ever in process of being moulded into its 

 specific forms by the continuous operation, through long ages, of laws 



* ride Qids, 1846, pp. 893 et seq. 



t " The Harmony of Animal Life, a Manifestation of Laws." By F. C. 

 Donders, 28th Jan., 1848. [Also in Dutch, never translated.] 



