42 SCIENTIST 



States. A single pinprick on the tip of a finger may give 

 rise to movements in almost all the muscles of the body, 

 to changes in blood pressure, heart rate, sweat secretion, 

 the movements of the intestinal tract, and so on. The par- 

 ticular pattern of response will be different depending on 

 circumstances, such as the number of times one has pricked 

 his finger before, whether or not one is holding something 

 valuable and fragile in the hand that is pricked, whether 

 or not there is someone nearby who is known to object 

 to displays of emotion, and so on. 



Every one of the events elicited by the pinprick tends 

 to elicit still other events which react back on the earUer 

 ones. The sudden withdrawal of the arm upsets the balance 

 of the body. Readjustments are made by the other arm, 

 the legs, and the trunk, and messages are sent from these 

 areas back to the original hand and arm which further 

 modify their behavior. The sudden rise of blood pressure 

 calls forth other reactions which keep it from going too 

 far. The Hst of actions, reactions, adjustments, and read- 

 justments is almost literally endless, for the total experi- 

 ence leaves memory traces in the nervous system which 

 make it very likely that one will avoid pinpricks more easily 

 in the future and react differently to those that do occur. 



Highly organized systems of this type appear to develop 

 what might be called a "life of their own" and have led 

 to the speculation that an organism or "whole" is more 

 than the sum of its parts. No one has yet succeeded in 

 developing a very good method for studying wholes as 

 such, without breaking them down into their parts. At 

 present the subject constitutes a sort of borderland between 

 science and philosophy. Two of the most obscure parts of 

 this domain are the phenomena of consciousness and free 

 will. Their very existence is often denied by orthodox 

 scientists, but there is hardly anything that seems more 



