THE FINAL SYSTEM! GALEN 



present the working of the innate attractive 

 and alterative powers of the organs, whereby 

 they take and transform whatever nutriment is 

 needed for their functions. Galen writes as 

 a physiologist or biologist^ though he has in 

 mind the medical usefulness of his matter. 

 The opening paragraph of the third book gives 

 his final summary of this subject: 



" It has been made clear in the preceding 

 discussion that nutrition occurs by an altera- 

 tion or assimilation of that which nourishes to 

 that which receives nourishment, and that 

 there exists in every part of the animal a 

 faculty which in view of its activity we call, in 

 general terms, alterative, or, more specifically, 

 assimilative and nutritive. It was also shown 

 that a sufficient supply of the matter which the 

 part being nourished makes into nutriment 

 for itself, is ensured by virtue of another 

 faculty which naturally attracts its proper 

 juice [humour] ; that that juice is proper to 

 each part which is adapted for assimilation, and 

 that the faculty which attracts the juice is 

 called, by reason of its activity, attractive or 

 epispastic. It has also been shown that assimi- 

 lation is preceded by adhesion, and this, again, 

 by presentation, the latter stage being, as one 



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