VIRCHOW AND EVOLUTION. 281 



lished between the expert and the public, and the slow and natural 

 process of leavening the social lump by discovery and discussion will 

 be displaced by something far less safe and salutary. On this count, 

 then, I claim acquittal, being for the moment on the side of Virchow. 



In a discourse delivered before the British Association at Liverpool, 

 after speaking of the theory of evolution applied to the primitive con- 

 dition of matter as belonging to " the dim twilight of conjecture," and 

 affirming that " the certainty of experimental inquiry is here shut out," 

 I sketch the nebular theory as enunciated by Kant and Laplace, and 

 afterward proceed thus : 



" Accepting some such view of the construction of onr system as X'^ohable^ a 

 desire immediately arises to connect the present life of our planet with the past. 

 "We wish to know something of our remotest ancestry. On its first detachment 

 from the sun, life, as we understand it, could not have heen present on the earth. 

 How, then, did it come there ? The thing to be encouraged here is a reverent 

 freedom — a freedom preceded by the hard discipline which checks licentiousness 

 in speculation — while the thing to be repressed, both in science and out of it, 

 is dogmatism. And here I am in the hands of the meeting, willing to end but 

 ready to go on. I have no right to intrude upon you unasked the unformed 

 notions tchich are floating like clouds or gathering to more solid consistency in 

 the modern speculative mindy 



I then notice more especially the theory of evolution : 



"Those who hold the doctrine of evolution are ly 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 

 proof of the illegality of the act, they prolong the method of Nature from the 

 present into the past. Here the observed uniformity of Nature is their only 

 guide. Having determined tlie elements of their curve in a world of observa- 

 tion 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." 



Thus it appears that, long antecedent to the publication of his advice, I 

 did exactly what Prof. Virchow recommends, showing myself as care- 

 ful as he could be not to claim for a scientific doctrine a certainty which 

 did not belong to it. 



I now pass on to the " Belfast Address," and will cite at once from 

 it the passage which has given rise to the most violent animadversion : 



" Believing as I do in the continuity of Nature, I cannot stop abruptly where 

 our microscopes cease to be of use. At tliis point the vision of the mind authori- 

 tatively supplements that of the eye. By an intellectual necessity I cross the 

 boundary of the experimental evidence, and discern in tliat 'matter' which we, 

 in our ignorance of its latent powers, and notwithstanding our professed rever- 

 ence for its Creator, have hitherto covered with opprobrium, the promise and 

 potency of all terrestrial life." 



Without halting for a moment I go on to do the precise thing which 

 Prof. Virchow declares to be necessary : 



