154 ESSAYS OF A BIOLOGIST 



it, and so laying the best possible foundations for future 

 repression. Or, on the other hand, they may openly 

 adopt the psycho-analytic view as to the role of sex 

 in the development of mind, may further believe that 

 the fullest analysis and self-knowledge is always 

 desirable, and may accordingly be pointing out to 

 the child interpretations of its actions and sayings 

 in terms of sex, familiarizing it with sex from the 

 outset, not merely not discouraging but actually 

 encouraging reference to sexual matters. This will 

 tend, ceteris paribus^ to the development of a mind 

 in which many of the more complex mental operations 

 will not usually persist because the subject will be 

 continually unbuilding them into their constituent 

 parts, of which sex will be the most unvarying and 

 important. 



Both these types are to my judgment obviously 

 unsatisfactory. The ideal organization of the mind 

 must be one in which first there is a minimum of 

 waste of energy, secondly a maximum realization of 

 potentiality. The operations of mind may further 

 be thought of from two different angles — as sub- 

 serving the biological needs of the organism, or as 

 ends in themselves. From the first point of view, 

 thought is action in posse : efficiency and full utiliza- 

 tion of energy are here the requirements, and it is 

 obvious that any method which even partially separates 

 one part of the mental organization from the rest 

 must be a poor one, that a refusal to face any portion 



