The Critique of Thomas Aquinas's Unicity Theory of Forms in John Pecham's Quodlibet IV (Romanum)

The Critique of Thomas Aquinas's Unicity Theory of Forms in John Pecham's Quodlibet IV (Romanum) During his lectorship at the Roman Curia (1277-1279), John Pecham, former master at Paris and Oxford, wrote his Quodlibet W (Romanum). In question 11 Pecham gave a critique of a certain formulation of the unicity theory of the number of human substantial forms. Although discussions between Franciscans and Dominicans on this issue are known to be quite acrimonious after the condemnations of 1277 and charges of theological heterodoxy would be exchanged, Pecham was a sharp critic of Thomas's unicity theory in Thomas's lifetime, and during Pecham's regency in Paris (1269-1270) there was an exchange between Pecham, the Franciscan, and Thomas, the Dominican. As a result of Pecham's critique of Thomas in 1270 at Paris, Thomas refined his position concerning the unicity of substantial forms and this revised version is presented only in Thomas's final works, specifically in the third part of the Summa, written in 1272-1273, shortly before Thomas's death in early 1274. Pecham's Quodlibet IV (Romanum) is his response to Thomas's final words on this issue. Thomas's initial formulation of the unicity theory, his 1270 exchange with Pecham and the other masters of Paris, the reformulated position in part three of the Summa, and the exact nature of Pecham's critique in Quodlibet W (Romanum) will identify Pecham's target in Quodlibet W (Romanum) not as Thomas's formulation prior to 1270, but his reformulation of the unicity theory after 1270, namely in part three of the Summa. I Thomas's unicity theory of the number of human substantial forms is well-known. Relying heavily on Aristotle, Thomas maintained that there was only one human substantial form, the rational soul which immediately informs matter. Thomas's theory is more than a psychological one, because Thomas raised the theory to a metaphysical level in which claims about being are asserted. In his Summa Thomas provided three distinct arguments for his theory of 423 Franciscan Studies Vol. 56 (1998) 424Gordon A. Wilson the unicity of forms. The first is metaphysical and is based upon the substantial unity of being. It is by one form that an individual exists and is one because form confers both being and unity.1 The second is a logical argument based on the nature of essential predication and accidental predication: that which is superior on the scale of predicates can be essentially attributed to what is inferior, but if an individual is not human and animal by the same form, one could not essentially predicate animality to humans, which is false.2 The third is a psychological argument based on one activity of the soul impeding another: only if there is one substantial form could a human's operation of understanding impede the operation of sensing.3 In the De spiritualibus creaturis, Thomas added a fourth argument, based on physics. For there to be true generation rather than superficial alterations, it is always necessary for matter to lose its unique form when it gains a new substantial form.4 During his lifetime the issue of the identity of a live and dead body, in particular the issue of the dead body of Christ in the tomb pushed Thomas's position to its limits. If there is but one substantial form of any particular human, the rational soul, then once the rational soul is separated from the body at death, the live body and the dead body are not the same, and not the same in number, since form accounts for identity in species. As a metaphysical theory, the claim that form confers both being and unity must be applicable to all beings. Concerning the dead body and live body of Christ Thomas wrote in his Quodlibet II: "Therefore it cannot be said that Christ's body was simply the same in number.... It is to be said then that it was the same secundum quid: the same according to matter, but truly not the same according to the form."5 Given the principles with which Thomas is operating, the following problem arises: how can matter be the...