40 E. L. THORNDIKE. 



The c^reat support of those who do claim for animals the 

 ability to infer has been their wonderful performances which 

 resemble our own. These could not, they claim, have hap- 

 pened by accident. No animal could learn to open a latched 

 gate by accident. The whole substance of the argument van- 

 ishes if, as a matter of fact, animals do learn those things by 

 accident. They certainly do. In this investigation choice was 

 made of the intelligent performances described by Romanes in 

 the following passages. I shall quote at some length because 

 these passages give an admirable illustration of an attitude of 

 investigadon which this research will, I hope, render impossible 

 for any scientist in the future. Speaking of the general intelli- 

 gence of cats, Romanes says : 



" Thus, for instance, while I have only heard of one solitary case 

 * * * of a dog which, without tuition, divined the use of a thumb-latch 

 so as to open a closed door by jumping on the handle and depressing 

 the thumb-piece, I have received some half-dozen instances of this 

 displav of intelligence on the part of cats. These instances are all 

 such precise repetitions of one another that I conclude the fact to be 

 one of tolerably ordinary occurrence among cats, w^iile it is certainly 

 very rare among dogs. I may add that my own coachman once had 

 a cat which, certainly without tuition, learnt thus to open a door that 

 led into the stables from a yard into which looked some of the win- 

 dows of the house. Standing at these windows when the cat did not 

 see me, I have many times witnessed her modus opera?idi. Walking 

 up to the door with a most matter-of-course kind of air, she used 

 to spring at the half hoop handle just below the thumb-latch. 

 Holding on to the bottom of this half-hoop with one fore paw, she 

 then raised the other to the thvunb-piece, and while depressing the 

 latter finally with her hind legs scratched and pushed the door-posts 

 so as to open the door * * *. 



" Of course in all such cases the cats must have previously ob- 

 served that the doors are opened by persons placing their hands upon 

 the handles and, having observed this, the animals act by what may 

 be strictly termed rational imitation. But it should be observed that 

 the process as a whole is something more than imitative. For not 

 only would obsei-vation alone be scarcely enough (within any limits of 

 thoughtful reflection that it would be reasonable to ascribe to an 

 animal) to enable a cat upon the ground to distinguish that the essen- 

 tial part of the process consists not in grasping the handle, but in 



