CELESTIAL MOVERS IN MEDIEVAL PHYSICS 173 



celestial motions. Nature as a formal principle always moves 

 toward a determined end, and when it has attained it, rests in 

 that attainment. " The reason for this is that nature does not 

 cause local motion except 'per consequens, for in moving toward 

 the form it consequently moves to the place which belongs to 

 its form." In the celestial motions there is never any attain- 

 ment and possession. " The mover of the heaven never moves 

 to any position, but to move out of it again. But to move into 

 a position and to move out of it again is not from nature, but 

 from soul." ^^ For this reason Albert frequently insisted that 

 celestial motions are not from nature, but from intelligence 

 (caeli motus non dicitur naturae motus, sed intelligentiae) .^^ 

 Albert undoubtedly would have admitted that celestial motions 

 are " natural " in the sense of coming from a passive principle, 

 the celestial body. But invariably he prefers to deny the natural 

 character of celestial motions, insisting always that they are not 

 from nature, but from soul or intelligence. Precisely because 

 the body itself is not the source of its perpetual movement, 

 it is said to be moved. " Everything which is moved has a 

 mover conjoined to itself, as was proved in the Seventh Book of 

 the Physicsr " 



The nature of the conjoined mover is difficult to determine 

 in the wi'itings of St. Albert, largely, no doubt, because Albert 

 retained the Aristotelian terminology while denying the sub- 

 stantial union of the two " parts " of the sphere. The con- 

 joined mover is clearly a spiritual substance, indivisible, and 

 separated from all matter, at least in definition .^^ It moves the 

 body by its knowledge and desire of something higher.®^ " Since 



*^ " Adhuc autem natura non movet nisi ad unum, et cum pervenerit, quiescit in 

 illo. Cuius causa est, quia natura non est causa motus localis nisi per consequens: 

 movendo enim ad formam, per consequens movet ad locum qui est illius formae. 

 Motor autem caeli non movet unquam ad aliquem situm, nisi moveat etiam ex illo. 

 In aliquid igitur movere et ex iUo non est naturae, sed animae." St. Albert, Lib. XI 

 Metaph., tr. I, c. 13, ed. cit., p. 605b. 



** St. Albert, Lib. II Phys., tr. I, c. 2, ed. cit., p. 95b. 



" St. Albert, Lib. XI Metaph., tr. II, c. 3, ed. cit, p. 614a; see Lib. VII Phys., 

 text et comm. 10. 



«' St. Albert, Lib. XI Metaph., tr. II, cc. 12-13. 



'"Ibid., c. 13, ed. cit., p. 605a. 



