ioo INSTINCTS 



learn to avoid all plants that may prick me. We 

 proceed to class as " properties " the similarities, 

 contiguities and sequences that were the funda- 

 mental points of attachment by which we first 

 linked our impressions together : similarity is 

 figured as relationship, connection in space as posi- 

 tion, sequence as cause and effect. I have learnt 

 when using a slate that a squeak is caused by (that 

 is to say, is preceded by) friction : I infer that the 

 squeaking of a tram-car is also caused by friction. 

 I suffered from headache when ascending a 

 mountain : I infer that a balloon ascent would 

 give me (that is to say, would be followed by) a 

 headache. Prodigious have been the consequences 

 to mankind, for evil as well as for good, of this 

 assumption that the links of inference are them- 

 selves properties. For, in discovering these links, 

 we are not assisted by instinct, but are left to our 

 powers of perception, and we are accordingly 

 liable to great error. I may confuse the dream of 

 a pain with an actual pain, and may wrongly infer 

 that I need medical treatment. I may perceive 

 the stars as lying close to one another, and may 

 imagine that they are " pattens of bright gold " 

 set in a crystal sphere. I may attribute an attack 

 of indigestion to lobster salad when it was really 

 caused by champagne. We are especially liable 

 to error when we see in happenings the property 

 of being causally connected with what precedes 

 them, since a happening is preceded not by a single 

 thing, but by a complicated tangle of things, out 

 of which we are liable to make a wrong selection, 

 and so to dignify as the "cause" of the happen- 

 ing a thing which had in reality no connection 

 with it. I may, for instance, infer that an old 

 woman is a witch because I felt queerly when I 

 passed her, and had read that witches, by the 

 evil eye, could affect malignantly those who 



