330 Animal Life and Intelligence. 



the subject ' air.' " The proposition always involves con- 

 ceptual elements; for the predicate of a proposition is 

 always an abstract idea or general notion. 



Propositions so formed may then become links in a 

 chain of reasoning. " To reason is," says Mr. Sully,* "to 

 pass from a certain judgment or certain judgments to a 

 new one." And so passing on from judgment to judgment, 

 we may ascend to the higher levels of abstract thought. 

 According to Mr. Sully's definition, therefore, we start from 

 a judgment or judgments in the process of reasoning. 

 The formation of a judgment (conceptual inference) is, 

 however, the first step in a continuous process ; and I pro- 

 pose, under this term, "reason," f to include this first step 

 also. The formation of a conceptual inference I regard as 

 the first stage of reason. Any mental process involving 

 conceptual inference I shall call rational. 



In contradistinction to this, I shall use the term " in- 

 telligence " for the processes by which perceptual inferences 

 are reached. An intelligent act is an act performed as the 

 outcome of merely perceptual inference. A rational act is 

 the outcome of an inference which contains a conceptual 

 element. 



* " Outlines of Psychology." p. 414. 



t Mr. Romanes adopts a different use of the terms " reason" and " rational," 

 to which allusion will be made in the nest chapter. 



