THE ANIMAL MIND 



origin only in the sense that man himself is of ani- 

 mal origin. They are not endowments from some 

 external or extra-human source. They must have 

 been potential in the lower orders just as our 

 limbs were potential in the fins of the fish, and our 

 lungs potential in its air-bladder. Evolution must 

 always have something to go upon, but that some- 

 thing may be quite beyond our human ken, as it 

 certainly is in the case of man's higher nature. It is 

 much easier to trace the feather of the bird to the 

 scale of the fish than it is to trace our moral nature 

 to its animal origin. Yet this is the only possible 

 source science can assign to it, because it is the only 

 source that falls within the sphere of physical causa- 

 tion, the only causation science knows. 



When the lower animals laugh, I shall believe 

 they have the faculty of reason also. Think how 

 long man must have lived before he became a laugh- 

 ing animal before he was sufficiently developed 

 mentally to take note of incongruities, or for this or 

 that object or incident to excite his mirth instead of 

 his fear! When I first saw a trolley-car running 

 along the street without any apparent means of 

 propulsion, it excited my surprise and curiosity. 

 When my horse first saw it, he was filled with alarm. 

 I do not suppose my horse had the same mental 

 process about it that I had; an effect without an 

 apparent cause could have been nothing to him. 

 He was moved simply by the strangeness of the 

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