144 DANIEL A. CALLUS 



which is in phmts; the sensitive soul, which is in dumb animals; 

 and the rational soul, which is in man alone. Yet there are not 

 three souls in man, as some think. According to these thinkers, 

 there are really three souls in man: the vegetative, the sensitive 

 and the rational. But this is untenable, for of one and the same 

 thing there cannot be but one first perfection, since one and 

 the same thing can have but one existence {unicum esse) . Now 

 all agree that the soul is the perfection of an organized body 

 holding life in potentiality. The vegetative soul, therefore, is 

 the perfection of this body, and likewise the sensitive and the 

 rational soul. It follows, then, that if there were three souls, 

 this body would be perfected in virtue of the first perfection, 

 which is impossible. Again, if the first endows the body with 

 its perfection, the second or the third would serve no purpose.*^ 

 Those who claim that there are three souls in man are per- 

 suaded by this reason: they see that the embryo, even before 

 it is perfected by the sensitive and the rational soul, grows. 

 But growth is exclusively caused by the vegetative soul. Con- 

 sequently, it seems that the vegetative soul is in the embryo 

 before the sensitive and the rational soul. They prove this from 

 the first proposition of the book De pwa bonitate. However, 

 they labor in vain {frustra nituntur) . The embryo is not self- 

 growing or vegetating, but grows in virtue of the mother, inas- 

 much as, previous to the infusion of the rational soul, it is in a 

 certain manner a part of the mother, since the embryo is united 

 to the matrix by cotyledons.^" Accordingly, it remains that the 



** " Neque sunt tres animae in homine, quemadmodum quidam putant. Dicunt 

 quod in homine est anima vegetabilis, et anima sensibilis, et anima rationalis. Sed 

 hoc non potest stare, quia unius rei unica est perfectio prima, quia unius rei 

 unicum est esse. Constat autem quod anima est perfectio corporis organici potentia 

 vitam habentis. Ergo haec anima vegetabilis est perfectio huius corporis, et haec 

 anima sensibilis, et haec anima rationalis. Ergo habet hoc unicum corpus vi per- 

 fectionis primae, quod esse non potest. Iterum, si prima perficit, pro nihilo 

 venit secunda vel tertia." Text edited by Dom O. Lottin, Psychologie et Morale 

 aux XW et XIW siecles, 2nd edition (Gembloux: Duculot, 1957) , p. 465. 



^^ See, e. g., Alexander Nequam, De naturis reruTn: " Cum enim cotilidonum nexu 

 familiari foetus adhaerens matrici quodammodo pars sit ipsius matris " (ed. cit., 

 p. 240) ; Albertus Magnus, De animalibus, XVI, tr. II, c. 7: " Qualiter per cottilidi- 

 ones fit incrementum embrionis " (ed. Stadler, 1131-3) ; and tr. I, c. 2. 



