Uniform Standard for Comparative Animal Psychology. 143 



many years in my room. Desiring to disaccustom the 

 ants from emerging through a certain opening of the 

 nest and falling upon a table from which it was difficult 

 for them to find the way home, I only had to grasp with 

 my pincers a number of ants, which happened to be out- 

 side, dip them into water and put them back, wet as they 

 were, into the nest. I could then be pretty sure that not 

 one of the several hundred ants of this colony would 

 dare to leave the nest for one or more days through the 

 dangerous opening. This fact proves that ants are un- 

 doubtedly able to make use of sensitive experiences, and 

 to communicate them to others of their species : indeed, 

 we do not find more " intelligence" even among higher 

 vertebrates. He who says that in such cases ants per- 

 form unconsciously adaptive actions, whilst similar ac- 

 tions of monkeys are consciously adaptive, makes an 

 arbitrary assumption that is not warranted by any reason 

 or argument. From equal effects we can and we must 

 infer equal causes. Consequently both ants and mon- 

 keys act only instinctively, or both of them perform in- 

 telligent actions. There is no other possible medium. 



It is, therefore, an unwarrantable inconsistency to 

 abandon the intelligence of ants, in order to save that of 

 the higher mammals. He who, with Ziegler, Smalian 

 and almost all modern animal psychologists styles all 

 those actions intelligent, which are due to the individual 

 experience of the animal, involves himself in an obvious 

 contradiction, by attributing "intelligence" only to higher 

 mammals and not to ants and other insects. For this 

 pretended intelligence is nothing more than the natural 

 exercise of innate instincts, by means of individual sense 

 perceptions. And for this reason all animals have more 



