on. v.] TEE TWO METHODS. 129 



shall admit only such conclusions as are not open to con- 

 troversy. Such a requirement would virtually prohibit 

 philosophy altogether. The difference between a scientific 

 and a metaphysical theorem is not that the former is not open 

 to controversy, but that it admits of verification ; it can, 

 either now or at some future time, be proved to be either 

 true or false. All such theorems may be admitted by a 

 scientific philosophy. Until they have been verified, we 

 may take account of them provisionally, as legitimate hypo- 

 theses : after they have been put to a crucial test, we may 

 either incorporate them with our philosophy or definitely 

 abandon them. Our philosophy, therefore, like all the sciences 

 whence it obtains the general truths which it seeks to organize 

 into a body of universal truth, may admit any number of 

 subjects of dispute ; but it can admit no question as a fit 

 subject of dispute, which, from the nature of the case, can 

 never be settled. It is perfectly in keeping, for example, for 

 two upholders of the Doctrine of Evolution, as well as for 

 two scientific specialists committed to no general doctrine, 

 to hold opposite views concerning the hypothesis of sponta- 

 neous generation. Since this is strictly a scientific hypothesis, 

 dealing solely with phenomena, and invoking no unknowable 

 agencies;- and since there is no reason, in the nature of 

 things, why it should not sooner or later be established or 

 overthrown by some crucial experiment ; there is nothing 

 anomalous in the fact of two such thoroughly scientific 

 evolutionists as Prof. Huxley and Dr. Bastian holding 

 opposite opinions as to its merits. But it would not be 

 in keeping for two scientific philosophers to wrangle over 

 Leibnitz's doctrine of Pre-established Harmouy, because that 

 is a hypothesis which can never be proved or ciisprcved. 

 The data necessary for its verification do not exist, and 

 therefore no system of philosophy, which would keep clear 

 of metaphysics, can recognize it as a legitimate subject for 

 investigation. Again, in the eighteenth century there were 

 vol. L K 



