NECESSARY BELIEFS. 67 



Mill's reply to McCosh, in the third edition of his 

 Examination of Hamilton'' s Philosophy ; and the reply 

 to Mill, in the appendix to McCosh's Defence of 

 Fundamental Truth, pp. 435-470.) He said to me 

 the other evening, what, he has often said publicly, 

 and what I therefore venture to quote : " The asso- 

 ciational school is disappearing. It soon will have 

 disappeared entirely. Schopenhauer and Hartmann, 

 too, will disappear. Hermann Lotze will not. It is 

 wise to keep now in the foreground the physiological 

 part of philosophy, for that is the battle-field of the 

 future." The defence of fundamental truth upon 

 which I am venturing here is based upon physiologi- 

 cal considerations quite as much as upon metaphysi- 

 cal. It is, in short, to stand upon that definition of 

 life which I hope was defended adequately in thir- 

 teen lectures which have already been given here on 

 Biology. 



Since there is nothing so good as eyesight for the 

 quenching of doubt on all biological questions, I beg 

 leave to surest to those who are not deficient in 

 leisure, that one of the best objects they can buy, in 

 these days of costly Christmas presents, is an efficient 

 microscope. There is more and more use of the 

 microscope by all students of philosophy. Some- 

 times serious interests are subserved even by the 

 amateur study of biology. You can in the few 

 evenings at your disposal, in a couple of years, make 

 yourselves competent to read the very best special- 

 ists in biological science. Until you read them, and 

 learn how to test their processes and to obtain 



