THE RELATIVITY OF KNOWLEDGE 



do we need any more evidence to convince us 

 that phenomena — by which I mean the effects 

 produced upon our consciousness by unknown 

 external agencies — are all that we can compare 

 and classify, and are therefore all that we can 

 know ? 



Perhaps, however, it may still appear that, in 

 the illustration just cited, we have assumed a 

 knowledge of the external cause, to a certain 

 extent. In asserting that the feelings of sound, 

 of heat, and of light are alike caused by vibra- 

 tions among particles of matter, we may perhaps 

 seem to imply that we do know these vibra- 

 tions, and we may be suspected of formulating 

 the various states of consciousness in question^ 

 in terms of the objective reality.^ But a mo- 

 ment's reflection will convince us that this is 

 not the case. After the illustration with which 

 this chapter opened, it is hardly necessary to say 

 that the knowledge of a vibration of particles as 

 an objective reality, is utterly unattainable by 

 us. We reach the conception of a vibration 

 of particles only by inference from the states of 



^ In his paper on ** Hibernicisms in Philosophy*' (^Con- 

 temporary Review y January, 1872, p. 147), the Duke of 

 Argyll himself commits the following exquisite bull : ** We 

 now know what Hght is * in itself — that is to say, we know 

 the nature and constitution of it, not in terms of the sensation 

 it gives to us, but in terms of a wholly different order of con- 

 ception.'*'* The italics are mine. 



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