INSTINCT AND INTELLIGENCE. 595 



predictions in order that the public may be informed as to the proba- 

 bilities of change. 



It may be said that in the last two or three cases the purpose is 

 intelligently appreciated, and that they are thus separated by a sharp 

 line from the others ; but this distinction gradually shades off and 

 disappears as an action becomes habitual, and as soon as the habit 

 becomes hereditary it may be entirely wanting. 



The well-drilled soldier goes through with his evolutions without 

 a thought as to his reasons for doing so, and nearly every middle-aged 

 business-man of methodical habits probably recollects finding himself 

 at his place of business on a holiday without knowing how or why 

 he came there. One characteristic of these various actions is, then, 

 that each has a purpose. Another is that, although the object of the 

 action is the accomplishment of a purpose, the cause of the action is 

 a change, external to the organism and distinct from the purpose. 



The leaf of the Venus's-flytrap closes, and the digestive organs 

 of an animal do their work, not because food is needed, but because 

 they are excited by the presence of a foreign body. The dog points 

 because he scents a particular odor, not because he wishes to do his 

 duty. The soldier assumes his position because he hears the word of 

 command, etc. The actions which are the subject of our present lect- 

 ure stand, tlien, in a double relationship. They are excited by cer- 

 tain external changes, and they have for their object the accomplish- 

 ment of a purpose. Herbert Spencer has expressed this dual rela- 

 tionship in a simple formula. According to him, these and all other 

 peculiarly vital actions consist in "the adjustment of internal rela- 

 tions to external relations." This is not very lucid when stated ab- 

 stractly, but perhaps an example will help to make it clear. If I 

 kick a stone, I may move it a greater or less distance, and set up some 

 slight molecular cliange within it, and hurt my foot, perhaps. If I 

 kick a dead dog, the result is the same ; but, if the dog is alive, I shall 

 find that all these results follow, and something more. The molecu- 

 lar change in the nerves of the dog gives rise to or excites a series of 

 actions adapted to meet my attack and to prevent further injury. 

 There is a relation, external to the dog, between the kick and a dispo- 

 sition to do him further violence ; and there is an internal relation in 

 the dog between the sensation caused by the blow and a desire to 

 escape the violence which is to follow ; and whether he crouches and 

 supplicates, or puts his tail between his legs and runs, or returns my 

 attack, he simply adjusts internal relations to external relations. 

 There is a relation between a downward direction and the presence of 

 water in the ground, and to this relation the roots of the plant re- 

 spond. 



There is a relation between the presence of a foreign body in the 

 stomach and food to be digested ; and accordingly, when the stom- 

 ach is excited by the sensation of contact with a foreign body, it be- 



