igo THE WONDER OF LIFE 



Above reflex actions of parts of the body may be ranked 

 a series of movements — often called tropisms — such, as 

 movements towards the Hght or away from it, towards 

 warmth or away from it, towards one chemical substance 

 and away from another. 



Then comes the great range of instinctive behaviour, 

 differing in a broad way from reflexes and tropisms in its 

 greater complexity of concatenation, differing in a broad 

 way from intelligence in its fixedness and in its indepen- 

 dence of experience. That it is very frequently influenced 

 by intelUgence is generally admitted. 



The higher grade of behaviour which we call intelligent 

 is marked by conscious control, by learning, by profiting 

 from experience, by ' perceptual inference ', and often by 

 experimenting. In the individual life-time a piece of 

 behaviour which required intelhgent control to start with 

 may by dint of repetition cease to require this and become 

 habitual. 



In some human actions there is a control of behaviour 

 in reference to general ideas, there is ' conceptual ' instead 

 of ' perceptual ' inference, and to this the term rational 

 conduct should be restricted. 



Behaviour looked at without Analysis. — Before going 

 further, it may be useful to look at the general busiaess of 

 animals, without raising any of the very difficult problems 

 regarding the relative status or significance of different 

 kinds of behaviour. What is it, on the whole, that animals 

 busy themselves with? We must answer, with Prof. 

 M. F. Guyer, that ' Animals, from their own point of view, 

 have two, and only two, occupations in the world. These 

 are (1) to care for themselves, and (2) to care for their 

 offspring. Consequently, every important thing to be 



