00100			BOOK REVIEW
00200	
00300		      Kenneth Mark Colby	
00400	
00500	PURPOSIVE EXPLANATION IN PSYCHOLOGY, Margaret A. Boden, Harvard
00600		University Press, Cambridge Massachusetts, 1972.
00700	
00800	
00900		Artificial  intelligence  is a type of theoretical psychology
01000	studying mental, symbol-processing functions in living and nonliving,
01100	real  and abstract systems. Psychology's methods have been limited to
01200	experimental,     survey,      mathematical,      interview,      and
01300	participant-observation  approaches.  A-I adds a new formal method in
01400	which theories are cast in the formalism of a  programming  language.
01500	Many  workers  in  A-I  lack  knowledge  about psychological theories
01600	relevant to their interests.  This is the perfect book for them.
01800		Boden,  a  Lecturer  in  psychology  and  philosophy  at  the
01900	University  of Sussex, England, provides a thorough and authoritative
02000	analysis of the concept of purpose which is fundamental in explaining
02100	both  human behavior and the behavior of computer models emulating or
02200	simulating it.   A great puzzle of the  past,  how  final  causes  or
02300	purposes  or  goals  can determine behavior, now becomes clear if one
02400	takes computer models as the  key  analogy.     For  it  is  not  the
02500	goal-state,  which  has  not  yet  come  into being, which determines
02600	behavior but a system's CONCEPT or  MODEL  of  the  goal-state  which
02700	directs its behavior. A convincing argument is then made to show that
02800	teleological and mechanistic explanations are complementary  and  the
02900	latter cannot replace the former without losing explanatory power.
03000		This scholarly work is packed with information not only about
03100	psychological  issues  central  to A-I but also about surrounding and
03200	beclouded philosophical problems. Our philosophy and even metaphysics
03300	should  be  clear to us because they influence the system of concepts
03400	we choose in trying to understand the world.
03500		Some of Dreyfus' inanities  and  confusions  are  dealt  with
03600	firmly and without malice, for example, his confounding of a symbolic
03700	code with the information coded.  Boden suggests  McDougall's  theory
03800	of the mind as an example of a rich theory to be simulated.   I would
03900	have some reservations about this task but only  because  the  theory
04000	seems   too   holistic.    Model  building  involves  a  strategy  of
04100	simplification   and   partial   approximation    by    investigating
04200	part-processes.  But it may be that in case of the mind, we will need
04300	all the parts or most of them to have an adequate simulation.
04400		I  not  only highly recommend this book - I would insist that
04500	any A-I theoretician worthy of the name must be familiar with it  and
04600	the  issues  it  addresses.   My  one  criticism  is  directed at the
04700	publisher who stodigly sticks to the convention of putting the  notes
04800	at the end of the book, requiring a serious reader to keep fingers in
04900	three positions as he awkwardly flips back and  forth  between  text,
05000	notes, and biliography.