474 On Mental Education. [1855. 



The self-education to which he should be stimulated by the 

 desire to improve his judgment, requires no blind dependence 

 upon the dogmas of others, but is commended to him by the 

 suggestions and dictates of his own common sense. The first 

 part of it is founded in mental discipline : happily it requires 

 no unpleasant avowals ; appearances are preserved, and vanity 

 remains unhurt ; but it is necessary that a man examine him- 

 self, and that not carelessly. On the contrary, as he advances, 

 he should become more and more strict, till he ultimately 

 prove a sharper critic to himself than any one else can be ; 

 and he ought to intend this, for, so far as he consciously falls 

 short of it, he acknowledges that others may have reason on 

 their side when they criticise him. A first result of this habit 

 of mind will be an internal conviction of ignorance in many 

 things respecting which his neighbours are taught, and that 

 his opinions and conclusions on such matters ought to be 

 advanced with reservation. A mind so disciplined will be 

 open to correction upon good grounds in all things t e\en in those 

 it is best acquainted with, and should familiarize itself with 

 the idea of such being the case ; for though it sees no reason 

 to suppose itself in error, yet the possibility exists. The mind 

 is not enfeebled by this internal admission, but strengthened ; 

 for if it cannot distinguish proportionately between the pro- 

 bable right and wrong of things known imperfectly, it will tend 

 either to be rash or to hesitate ; whilst that which admits the 

 due amount of probability is likely to be justified in the end. 

 It is right that we should stand by and act on our principles ; 

 but not right to hold them in obstinate blindness, or retain 

 them when proved to be erroneous. I remember the time 

 when I believed a spark was produced between voltaic metals 

 as they approached to contact (and the reasons why it might be 

 possible yet remain) ; but others doubted the fact and denied 

 the proofs, and on re-examination I found reason to admit 

 their corrections were well-founded. Years ago I believed 



O 



that electrolytes could conduct electricity by a conduction 

 proper; that has also been denied by many through long 

 time : though I believed myself right, yet circumstances have 

 induced me to pay that respect to criticism as to reinvestigate 

 the subject, and I have the pleasure of thinking that nature 

 confirms my original conclusions. So though evidence may 



