The Metaphysics of Christology in the Late Middle Ages: William of Ockham to Gabriel Biel by Richard Cross (review)

Reviewed by: The Metaphysics of Christology in the Late Middle Ages: William of Ockham to Gabriel Biel by Richard Cross Mark Mattes The Metaphysics of Christology in the Late Middle Ages: William of Ockham to Gabriel Biel. By Richard Cross. Oxford: Oxford University Press, 2023. 320 pp. + xx. In several recent books, Richard Cross explores the Western medieval adoption of an Aristotelian metaphysical approach to understanding the incarnation. This volume contributes to his enterprise by focusing on late medieval thinkers, many of whom took their End Page 76 bearings from either Aquinas or Scotus. Cross notes that the metaphysical Christological forays of the later Middle Ages reflect less innovation and more consolidation of what can be called the opinio communis in which the union between the human and the divine natures in the one person of Jesus Christ is likened to that of an Aristotelian view of how a trait or "accident" is related to a substance. The key idea is that an accident depends on a substance to hold or sustain it, while the accident "informs" the substance. Cross notes that Martin Luther did not diverge from the metaphysical Christology of the opinio communis (4), though, in response to Cross, we must highlight that he clearly found the model of substance and accident as inadequate for describing the hypostatic union. In Chalcedonian orthodoxy, the suppositum of Christ is the same as that of the eternal Son, and, as incarnate, is composed of two natures, the divine, which he possessed from eternity, and the human, which he assumed in the incarnation. Christ has assumed a human nature, but, to be clear, not a human person. If there were two persons in the Word, one divine and one human, the resulting Christology would be Nestorian. Late medieval theologians debated how these two natures related to each other in the Word. While a majority of thinkers upheld the substance/accident model sanctioned in the opinio communis, others instead saw the hypostatic union as akin to the relation between whole and part or between the body and the soul in humans. Though not discussed in this book, Luther favored the model of heated iron, where neither substance loses its identity but instead the traits of each inform one another. This latter approach is not developed by the thinkers Cross outlines. Nevertheless, Cross thoroughly shows that these theologians, including major figures like Scotus and Ockham, and secondary figures such as Hervaeus Natalis, Walter Chatton, Robert Holcot, Peter of Ailly, Gregory of Rimini, Gabriel Biel, and John Capreolus, worked within the opinio communis. Cross also examines dissenters such as Peter Auriol who rejected the widespread assumption that the hypostatic union is grounded in the category of relation because he feared it would lead to an infinite regress of relations. As an alternative, he devised an even more abstract theory of hypostatic union, a geometrical model in which the two natures are unified like segments in a End Page 77 quantifiable linearity (212). Luther scholars will note that a number of the thinkers Cross outlines influenced Luther's Christology and sacramentology. Cross painstakingly explores the similarities and differences among these theologians, and how they impacted each other, and by implication, later Christologies. An interesting development among some of these thinkers is the speculative question of whether or not God could have united himself to a non-rational nature. For instance, could God have assumed the person of an ass ("asinus Christology")? Arnold of Strelly responded that if God were to assume the person of an ass, then that would entail that an ass would be a person. But that simply is not true (91). Hence, God could assume no non-rational nature. Given the Reformation heritage of a more biblical approach to Christology as well as the anti-metaphysical legacy of Kant, many Lutherans are apt to dismiss the scholastic machinations described in this book. Indeed, many of the debates described here seem to address the explanatory horizons of Aristotelianism rather than the soteriological impact of the incarnation. That said, it is impossible to read Luther's later Christological disputations and his response to Zwingli's view of the Lord's Supper independently of metaphysics. Hence...