PREFATORY NOTE. 



and grandeur ; to the men who cannot overlook those 

 small exceptions and insignificant residual phenomena 

 which, when tracked to their causes, are so often the 

 death of brilliant hypotheses ; to the men, finally, who, 

 by demonstrating the limits to human knowledge 

 which are set by the very conditions of thought, have 

 warned mankind against fruitless efforts to overstep 

 those limits. 



Neither of the eminent men of science, whose 

 opinions are at present under consideration, can be 

 said to be a one-sided representative either of the 

 synthetic or of the analytic school. Haeckel, no less 

 than Virchow, is distinguished by the number, variety, 

 and laborious accuracy of his contributions to positive 

 knowledge ; while Virchow, no less than Haeckel, has 

 dealt in wide generalisations, and, until the obscuran- 

 tists thought they could turn his recent utterances to 

 account, no one was better abused by them as a 

 typical free-thinker and materialist. But, as hap- 

 pened to the two women grinding at the same mill, 

 one has been taken and the other left. Since the pub- 

 lication of his famous oration, Virchow has been received 

 into the bosom of orthodoxy and respectability, whi^e 

 Haeckel remains an outcast ! 



To those who pay attention to the actual facts of the 

 case, this is a very surprising event ; and I confess tha t 

 nothing has ever perplexed me more than the reception 



