The Medieval Heritage in Early Modern Metaphysics and Modal Theory, 1400-1700 (review)

This volume contains contributions that aim to show the continuity between late medieval thought and early modern philosophy, or, as the editors say, to investigate "the way that medieval thought served as a fertile basis for developments in the early modern period" (3). As the title indicates, most papers treat topics more or less connected to modalities, either from a logical or from an ontological point of view. The nature of modalities is indeed at the core of metaphysics and philosophical theology. Ludger Honnefelder, Joël Biard, and Fabrizio Mondori all show the influence of Duns Scotus on the setting of modern metaphysics. The importance of theological matters in the development of philosophical thought has been acknowledged for a long time. Thus Chris Schabel ("Divine Foreknowledge and Human Freedom: Auriol, Pomponazzi, and Luther on 'Scholastic Subtleties'") sketches the story of the controversy over God's foreknowledge and future contingents from its setting in the early fourteenth century to Lutheran Reformation. He stresses the underestimated influence of Peter Auriol in this continuing debate. Still, revealed theology too exercised influence on the philosophy of logic. Trinity constitutes an until now little studied case, which is the subject matter of Simo Knuuttila's contribution ("The Question of the Validity of Logic in Late Medieval Thought"). He partly rehearses some of his well-known theses about the source of logical truths and modalities and analyses the constructivist aspects of Descartes's position, in so far as the laws of logic are said to depend on God's will. But the most original part of the study bears on the effects of Trinitarian constraints within the field of logic, especially in syllogistics. Medieval thinkers had to cope with syllogisms like: "The divine essence is the father; the divine essence is the Son; therefore the Son is the Father." In order to avoid the absurdity of the conclusion, many answers were elaborated: Robert Holcot removed the Trinity from the domain of validity of syllogistics, thereby relativizing it. Luther's claim that the principles of theology contradict those of logic looks like a radical version of this position. Adam Wodeham maintained contrariwise the universality of syllogistics: he held that the premisses are not syllogistic if they are interpreted as true (130). His account is based on the identity theory of predication and on the distinction between intensional and extensional identity, which both date back to Abelard.

In the period covered by the volume, early modern scholastic, chiefly the Jesuit scholastic, holds a central place. Two articles insist on its originality and intrinsic value. Jeffrey Coombs ("The Ontological Source of Logical Possibility in Catholic Second Scholasticism") analyzes the various metaphysics of modalities. He claims that three theories of the source of logical modalities were entertained during the early seventeenth century, which he labels respectively "transcendentalism," "modal voluntarism," and "divine conceptualism." All of these positions can be traced back to medieval theories; however, they received an extensive treatment in late scholastic thought. Coombs is especially illuminating when he emphasizes the importance of the grounding metaphysical structure: essences and their systematic relations through "Porphyrian trees." This generated two different accounts of the ontological status of essences: according to essentialist theories, complete Porphyrian trees are the basis of necessity and possibility, while according to a "string theories," only the logical connections between the components of the essential structure are available eternally (196).

Yet the most striking novelty of the time lies in the systematization of a statistical interpretation of modalities through the "moral modalities," originating in post-Tridentine Catholic theology. In contrast to Hacking's thesis (see The Taming of Chance [Cambridge, 1990]), Sven Knebel ("The Renaissance of Statistical Modalities in Early Modern Scholasticism") contends that the concept of aleatory probability was first developed within this context. That an event-type Q is morally necessary means that Q is always the case, and that not-Q actually is never the case (236...