468 On Mental Education. [1855. 



So, error results occasionally from believing our senses : it 

 ought to be considered, rather, as an error of the judgment 

 than of the sense, for the latter has performed its duty ; the 

 indication is always correct, and in harmony with the great 

 truth of nature. Where, then, is the mistake? almost entirely 

 with our judgment. We have not had that sufficient instruc- 

 tion by the senses which would justify our making a conclusion ; 

 we have to contrive extra and special means, by which their 

 first impressions shall be corrected, or rather enlarged ; and it 

 is because our procedure was hasty, our data too few, and our 

 judgment untaught, that we fell into mistake ; not because 

 the data were wrong. How frequently may each one of us 

 perceive, in our neighbours, at least, that a result like this, 

 derived from the observation of physical things, happens in 

 the ordinary affairs of common life ! 



When I become convicted of such haste, which is not 

 unfrequently the case, I look back upon the error as one of 

 ' presumptuous judgment.' Under that form it is easily pre- 

 sentable to the mind, and has a useful corrective action. I do 

 not think the expression too strong ; for if we are led, either 

 by simplicity or vanity, to give an opinion upon matters 

 respecting which we are not instructed, either by the know- 

 ledge of others, or our own intimate observation ; if we are 

 induced to ascribe an effect to one force, or deny its relation 

 to another, knowing little or nothing of the laws of the forces, 

 or the necessary conditions of the effect to be considered ; 

 surely our judgment must be qualified as ' presumptuous.' 



There are multitudes who think themselves competent to 

 decide, after the most cursory observation, upon the cause of 

 this or that event (and they may be really very acute and 

 correct in things familiar to them) : a not unusual phrase 

 with them is, that * it stands to reason' that the effect they 

 expect should result from the cause they assign to it, and yet 

 it is very difficult, in numerous cases that appear plain, to 

 show this reason, or to deduce the true and only rational 

 relation of cause and effect. In matters connected with natural 

 philosophy, we have wonderful aid in the progress and assurance 

 in the character, of our final judgment, afforded us by the facts 

 which supply our data, and the experience which multiplies 

 their number and varies their testimony. A fundamental fact, 

 like an elementary principle, never fails us, its evidence is 



