MEDICINE AND PHILOSOPHY 11 TH AND 12TH CENTURIES 119 



After the first systematic commentaries on the newly trans- 

 lated scientific writings of Aristotle had appeared in the latter 

 half of the thirteenth century, the problem of elements began 

 to emerge again, and all the opposed conceptions were formu- 

 lated in terminology borrowed from the Aristotelian writings. 

 The discussion of least parts and simples in terms of kinds of 

 motion led into theories of minima and viaxima, and of simples 

 and composites; the discussion of numbers and mathematical 

 bodies as least parts and organizing principles of composites 

 and organisms went from Platonic beginnings to mathematical 

 elaborations; the Stoic elements and their efficient principles 

 and the arbitrary models which used methods familiar to the 

 skeptics were known in the Renaissance; the Epicurean atoms 

 moving in a void were set forth by Gassendi in the seventeenth 

 century. With the progress of medicine, astronomy, and me- 

 chanics in the Renaissance attention concentrated on the ele- 

 ments as principles again, and Boyle was able to assemble in 

 the dialogue of the Sceptical Chymist a Corpuscularian, a 

 Peripatetic, and a Spagyrist or modern Chemist, to discuss a 

 large variety of theories of elements (including van Helmot's 

 theory that all things are water fructified by seeds) . 



The transition from the Renaissance to the seventeenth cen- 

 tury is similar in what happened to the treatment of elements 

 to the transition from the twelfth to the thirteenth century: 

 more was known and the data were richer, but the opposed 

 theories followed a similar pattern, and the discussion of 

 elements again yielded to the discussion of laws and principles 

 of motion — the issue in the seventeenth century was not pri- 

 marily between Descartes' vortices, Leibniz' monads, and 

 Newton's atoms but between their conceptions of mass and 

 motion and their elaborations and applications of laws of 

 motion. The Newtonian principles were used to organize a 

 system of the world and a system of physical science in the 

 eighteenth and early nineteenth centuries, but in the twentieth 

 century our attention has turned again to elements and par- 

 ticles and to more subtle and better grounded forms of anti- 



