Preliminary Definitions and Ilhistrations. 27 



advantages and disadvantages of each, and to adopt one or 

 the other. I am quite convinced that, from the biological 

 point of view, it is more satisfactory to restrict the term 

 " instinctive " to those activities which are in greater or 

 less degree congenitally definite, and it is in this sense 

 that the phrase "instinctive activities" will be used in 

 this work. No doubt there are in many cases difficulties 

 of interpretation ; but these must be met as they arise in 

 the further prosecution of our studies. 



It may be convenient to indicate the nature of the 

 suggested classification in tabular form : — • 



Inhekited. 



Congenitally definite activities, Innate capacity, involving (a) a 

 under which those termed " in- power of association, and (6) 



stinctive" are comprised. hereditary susceptibilities to 



pleasure and pain. 



ACQUIEED. 



(a) Confirmation, or Particular application of innate 



(6) Modification, of congenitally capacity; 



definite or instinctive activi- (a) Occasional and under special 



ties so as to render them circumstances; 



habitual by repetition. (6) Frequently repeated, with the 



(c) Suppression of congenital ac- consequent formation of acquired 



tivities. habits. 



We may now sum up what has been advanced in the 

 foregoing discussion, and say that from the biological point 

 of view (and it is from this standpoint alone that they have 

 been so far considered) instincts are congenital, adaptive, 

 and co-ordinated activities of relative complexity, and 

 involving the behaviour of the organism as a whole. They 

 are not characteristic of individuals as such, but are 

 similarly performed by all like members of the same 

 more or less restricted group, under circumstances which 

 are either of frequent recurrence or are vitally essential 

 to the continuance of the race. While they are, broadly 

 speaking, constant in character, they are subject to 



