ISO DISCOURSE ON THE STUDY 



exists a much, more fundamental reply to this ob- 

 jection. In reasoning upon our observations, the 

 existence and possible amount of quantitative error 

 is always to be allowed for ; and the extent to which 

 theories may be affected by it is never to be lost 

 sight of. In reasoning upwards, from observations 

 confessedly imperfect to general laws, we must 

 take care always to regard our conclusions as con- 

 ditional, so far as they may be affected by such 

 unavoidable imperfections ; and when at length we 

 shall have arrived at our highest point, and attained 

 to axioms which admit of general and deductive 

 reasoning, the question, whether they are vitiated 

 by the errors of observation or not, will still remain 

 to be decided, and must become the object of sub- 

 sequent verification. This point will be made the 

 subject of more distinct consideration hereafter, 

 when we come to speak of the verification of theories 

 and the laws of probability. 



(125.) With respect to our record of observations, 

 it should be not only circumstantial but fait/tfzil ; by 

 which we mean, that it should contain all we did 

 observe, and nothing else. Without any intention of 

 falsifying our record, we may do so unperceived by 

 ourselves, owing to a mixture of the views and lan- 

 guage of an erroneous theory with that of simple fact. 

 Thus, for example, if, in describing the effect of" 

 lightning, we should say, " The thunderbolt struck 

 with violence against the side of the house, and beat 

 in the wall," a fact would be stated which we did 

 not see, and would lead our hearers to believe that a 

 solid or ponderable projectile was concerned. The 

 " strong smell of sulphur," which is sometimes said 



