CELESTIAL MOVERS IN MEDIEVAL PHYSICS 179 



Again [Avicenna] erred' on the subject of the animation of the 

 heavens. For he held that the heavens were animated. He said 

 that the soul of the heavens is not only a suitable moving power, as 

 the Philosopher and the Commentator were intent upon saying, 

 but that a single being is produced by the union of the soul of the 

 heavens with the heavens, just as by the union of our soul and 

 our body.^' 



Concerning this presumed view of Aristotle, Kilwardby notes 

 that it is philosophically sound and supported by reason: 

 " since those bodies seem to be more noble than living bodies, 

 they ought to have a higher form of life." Nevertheless in 1277 

 the Bishop of Paris condemned the proposition " that celestial 

 bodies are moved by an intrinsic principle, which is a soul." ^^ 

 And St. Albert, as we have seen, clearly rejected celestial ani- 

 mation as alien to the Catholic faith. 



The second opinion listed by Kilwardby is in reality that of 

 St. Thomas: " others hold that those bodies are moved by 

 angelic spirits who govern and move them in such a way that 

 they are not their act, or form." Kilwardby dismisses this view 

 as unphilosophical, and he remarks, " Nor do I recall it being 

 approved by any of the Sancti as true and certain." However, 

 Kilwardby does admit in passing that it could be held absque 

 error e by Catholics.^* 



Kilwardby 's own view of celestial motion is presented suc- 

 cinctly as the third opinion: 



Just as heavy and light bodies are moved to a place in which they 

 rest by their own inclinations and tendencies, so celestial bodies 

 are moved circularly in place by their own natural inclinations 

 similar to weight {quasi ponderibus) in order to conserve corrup- 

 tible things lest they suddenly perish and fail. 



Some spheres rotate naturally from West to East, others from 



®° Giles of Rome, Errores phUosophorum, VI: Avicenna, 10, ed. Josef Koch, trans, 

 by J. O. Riedl (Milwaukee: Marquette, 1944), p. 31. 



** Chartularium Univ. Paris., ed. H. Denifle, 0. P., I, n. 473, p. 548, prop. 92; 

 see also prop. 213. Cf. E. Krebs, Meister Dietrich, in Beitrdge z. Gesch. d. PhU. d. 

 M.-A., Bd. V, heft 5-6 (Miinster, 1906), pp. 75-76. 



** Cf. J. A. "Weisheipl, " The Problemata Determinata Ascribed to Albertus 

 Magnus," loc. cit., p. 304, note 8. 



