FOREWORD 



Aristotle refers to the De partibiis animalium as an 

 inquiry into the causes that in each case have deter- 

 mined the composition of animals. He does not, 

 however, employ the category of causation in the 

 manner normally adopted by men of science, since 

 in this book caus es are always considered in relati on 

 to ends or purpose s, and design is reg^arded as havi ng 

 had~a far larger share in the origin and developn^ nt 

 of l iving struct ures tnan that allotted to ji£C£asity. 



In the Histona animalium the parts themselves are 

 described, for although this work is to some extent 

 physiological, its main object was to deal with the 

 anatomy of the organism. The D<? pa riibus animalium , 

 on the other hand, is almost^ exghisivelyiphyj&ieleg^ical 

 and tele ological, and trea ts of the fu nctioiiS-QfL the 

 parts. But Aristotle's position was that o f a telep - 

 logist only in a li mited degrj ej_iiQr_iieapppRrs.,to 

 h avie fak^ jOhaT view ot life whjc hBergson calls_jthe 

 doctriryeo f internal j^n^ lity^ (that is to say, that each 

 indTvTdTiaTToratany rate each species, is made for 

 itself, that all its parts conspire for the greatest good 

 of the whole, and are intelligently organized in view 

 of that end but wi thout regard for othe r_or^a]Qlsms 

 or kinds of organisms). Since every organ or part 

 of the body was held to have its peculiar function, 

 the existence of vestigial or rudimentary organs M^as 



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