THINGS DENOTED BY NAMES. 85 



cannot both signify the same thing, namely, the 

 impression or feeling with which we are affected 

 through our senses by the presence of an object : 

 although there is at least no absurdity in supposing 

 that this identical impression or feeling may be called 

 a sensation when considered merely in itself, and a 

 quality when regarded as emanating from any one 

 of the numerous objects, the presence of which to our 

 organs excites in our minds that among various other 

 sensations or feelings. And if this be admissible as a 

 supposition, it rests with those who contend for an 

 entity per se called a quality, to show that their 

 opinion is preferable, or is anything in fact but a 

 lingering remnant of the scholastic doctrine of occult 

 causes ; the very absurdity which Moliere so happily 

 ridiculed when he made one of his pedantic physicians 

 account for the fact that " 1'opium endormit, " by the 

 maxim " parcequ'il a une vertu soporifique." 



It is evident that when the physician stated that 

 opium had "une vertu soporifique," he did not 

 account for, but merely asserted over again, the fact 

 that it endormit. In like manner, when we say that 

 snow is white because it has the quality of whiteness, 

 we are only re-asserting in more technical language 

 the fact that it excites in us the sensation of white. 

 If it be said that the sensation must have some cause, 

 I answer, its cause is the presence of the . object. 

 When we have asserted that as often as the object is 

 present, and our organs in their normal state, the 

 sensation takes place, we have stated all that we know 

 about the matter. There is no need, after assigning 

 a certain and intelligible cause, to suppose an occult 

 cause besides, for the purpose of enabling the real 

 cause to produce its effect. If I am asked, why does 



