3 o6 HERMANN VON HELMHOLTZ 



as I have put before you, who instils into his students wherever 

 possible the principle, "A metaphysical conclusion is either 

 a fallacy or a masked empirical inference," will not be viewed 

 with much favour by the believers in metaphysics and a priori 

 intuition, need hardly be expatiated on. Metaphysicians, like 

 all who have no definite reasons to set against their opponents, 

 are not generally very courteous in their polemic ; one's own 

 progress can indeed be estimated by the rising discourtesy 

 of the opposition': and even if he met these discourteous 

 scientific rejoinders with the dignity of a great thinker, the 

 unqualified attacks upon his person and his family had none 

 the less a depressing effect on him, and Helmholtz at this time 

 passed through a critical period. 



The entire University of Berlin united solidly with him, as 

 the Philosophical Faculty had on a previous occasion. 

 He, who had so recently joined its ranks, was elected 

 Rector in the year 1876, and this marked witness to the con- 

 fidence and respect of the many distinguished scientists who 

 belonged at that time to the Berlin University restored his 

 calm and contentment. He went to Switzerland for rest and 

 refreshment, taking long walks over the Grimsel and Eggisch- 

 horn to Belalp, where he stayed with Tyndall, on to Zermatt, 

 and thence with his wife to Stresa, Milan, Spezia, and 

 Rome. 



On this journey he composed the discourse which he de- 

 livered on October 15, 1877, when he assumed the Rectorate, 

 ' On the Academic Freedom of the German Universities.' It 

 expressed the spirit that was especially cherished and fostered 

 by the Universities of Germany, and which Helmholtz put into 

 words at a much later time in his Congratulatory Address to the 

 Academy on the occasion of du Bois-Reymond's jubilee : ' The 

 younger generation are taught that ideal aims are attainable 

 even in this life, and bring their reward, but only when they are 

 worked for in the right way.' The lecture is of extreme 

 interest, since it reveals the high moral, religious, and political 

 standpoint to which Helmholtz adhered during his whole life, 

 without taking up any public attitude in regard to these 

 questions. 



For Helmholtz, the power of a nation lies not merely in its 

 store of provender and money, its cannon and war-ships, but 



