OBSERVATION AND DESCRIPTION. 203 



bling him in appearance, as, at the distance, and with 

 the degree of attention which I bestowed, to be mis- 

 taken for him. I might have been asleep, and have 

 dreamed that I saw him; or in a state of nervous 

 disorder, which brought his image before me in a 

 waking hallucination. In all these modes men have 

 been led to believe that they saw persons well known 

 to them, who were dead, or far distant If any of 

 these suppositions had been true, the affirmation that 

 I saw my brother would have been erroneous; but 

 whatever was matter of direct perception, namely the 

 visual sensations, would have been real. The infe- 

 rence only would have been ill grounded ; I should 

 have ascribed those sensations to a wrong cause. 



Innumerable instances might be given, and ana- 

 lyzed in the same manner, of what are vulgarly 

 called errors of sense. There are none of them 

 properly errors of sense ; they are erroneous inferences 

 from sense. When I look at a candle through a 

 multiplying glass, I seem to see a dozen candles 

 instead of one : and if the real circumstances of the 

 case were skilfully disguised^ I might suppose that 

 there were really that number ; there would be what 

 is called an optical deception. In the kaleidoscope 

 there really is that deception : when I look through 

 the instrument, instead of what is actually there, 

 namely a casual arrangement of coloured fragments 

 of glass, I seem to see the same combination several 

 times repeated' in symmetrical arrangement round a 

 point. The delusion is of course effected by giving 

 me the same sensations, which I should have had if 

 such a symmetrical combination had really been pre- 

 sented to me. If I cross two of my fingers, and bring 

 any small object, a marble for instance, into contact 

 with both, at points not usually touched simultaneously 



