REASON 



99 



REASON. In man, as already remarked, in- 

 stinctive machinery for the regulation of outward 

 conduct has become obsolete. In exchange he 

 is equipped with Reason far more generously than 

 any other animal. In attempting to define 

 this faculty we enter upon ground which is strewn 

 with the fragments of psychological discussion. It 

 may, perhaps, be described as a process by which 

 we weave our impressions and recollections into 

 a connected tissue, instead of leaving them as a 

 tangled mass of random happenings. To this 

 end we are, in the first place, impelled to link 

 together different impressions by their similarity 

 of appearance, or by their contiguity in space, or 

 in time that is to say, we associate impressions 

 that resemble one another, are related in space to 

 one another, and precede or follow one another. 

 We connect in this way one dog with another dog, 

 a dog w r ith its kennel, and a dog with a bite. In 

 the next place we are impelled to infer that like- 

 ness in appearance implies likeness in what pre- 

 cedes, accompanies, or follows. I have been 

 pricked by a bramble : I infer that if I touch that 

 bramble, or another similar bramble, I shall be 

 pricked again. I have, then, learnt to avoid what 

 an insect would have avoided instinctively. But 

 with my reasoning powers at this stage I have to 

 learn a separate lesson for each particular set of 

 objects. My learning gains in scope immensely 

 when my reasoning powers are completed by an 

 impulse to distinguish things by their properties, 

 instead of accepting them as indivisible wholes, 

 and to see in these properties the causes^ of hap- 

 penings. I observe that the bramble has the 

 property of thorniness, and, by attaching my 

 inference not to the plant, but to the property, I 



1 To recognize, for instance, a soporific property in opium as the 

 cause of its inducing sleep. 



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