76 HUME 



II 



lively perceptions, when we hear, see, feel, love, 

 or will ; " in other words. " all our sensations, 

 passions, and emotions, as they make their first 

 appearance in the soul " (I. p. 15). 



" Ideas," on the other hand, are the faint images 

 of impressions in thinking and reasoning, or of 

 antecedent ideas. 



Both impressions and ideas may be either 

 simple, when they are incapable of further 

 analysis, or complex, when they may be resolved 

 into simpler constituents. All simple ideas are 

 exact copies of impressions ; but, in complex ideas, 

 the arrangement of simple constituents may be 

 different from that of the impressions of which 

 those simple ideas are copies. 



Thus the colours red and blue and the odour of 

 a rose, are simple impressions ; while the ideas of 

 blue, of red, and of rose-odour are simple copies of 

 these impressions. But a red rose gives us a 

 complex impression, capable of resolution into the 

 simple impressions of red colour, rose-scent, and 

 numerous others ; and we may have a complex 

 idea, which is an accurate, though faint, copy of 

 this complex impression. Once in possession of 

 the ideas of a red rose and of the colour blue, we 

 may, in imagination, substitute blue for red ; and 

 thus obtain a complex idea of a blue rose, which 

 is not an actual copy of any complex impression, 

 though all its elements are such copies. 



Hume has been criticised for making the 



