28 o 
Thoughts on our Conceptions [Ap r ^> 
to discover multitudes of errors that would otherwise escape 
their attention. This does not tend to make the results of 
their investigations less weighty than results which have 
been reached by other processes more purely mental. If 
men of science, with their severe methods of research, their 
habits of testing their conclusions by observation and expe- 
riment, are nevertheless led into wrong conclusions, what 
does it prove ? Simply that the human mind, even under 
the most favourable circumstances, is fallible ! Is there a 
class of men less liable to make mistakes ? It is precisely 
this experience which causes many to place a small value 
upon the unsupported assertions and speculations of any 
man, however honest, earnest, or able he may be. 
On this point one of the most admirable of experimenters, 
Faraday, has beautifully said — “ The world little knows how 
many of the thoughts and theories which have passed 
through the mind of the scientific investigator have been 
crushed in silence and secrecy by his own severe criticism 
and adverse examination ; that in the most successful in- 
stances not a tenth of the suggestions, the hopes, the 
wishes, the preliminary conclusions, have been realised.” 
In the 24th series of his “ Experimental Researches ” 
Faraday describes many tedious and intricate experiments, 
in which he tried to conned! gravitation and electricity. 
“ He laboured with characteristic energy for days, on the 
clock-tower of the Houses of Parliament and in the shot- 
tower of Southwark, raising and lowering heavy weights 
connected with wire coils. Many times his great skill as 
an experimenter prevented him from being deceived by 
results which others would have regarded as conclusive 
proofs of his idea, and when the whole was done there 
remained absolutely no result.” For although the results 
were wholly negative, Faraday could never accept them as 
conclusive against his idea, to which he had been led by his 
experiments on the relations between electricity and mag- 
netism. His mental condition after this work was done is 
best described in his own words : — “ Occasionally, and fre- 
quently, the exercise of the judgment ought to end in 
absolute reservation . It may be very distasteful, and great 
fatigue to suspend a conclusion ; but as we are not infallible, 
so we ought to be cautious.” 
It is a matter of common observation that men who, like 
Faraday, have done much to widen the boundaries of our 
knowledge, are precisely the ones who are most frequently 
in a state of doubt, while those who have received all their 
knowledge at second hand are generally more ready with a 
