Aquinas’s first proof for God’s existence is usually interpreted as a metaphysical argument immune to any objections coming from empirical science. Connections to Aquinas’s own historical understanding of physics and cosmology are ignored or downplayed. Nature and Nature's God proposes a natural philosophical interpretation of Aquinas’s argument more sensitive to the broader context of Aquinas’s work and yielding a more historically accurate account of the argument. Paradoxically, the book also shows that, on such an interpretation, Aquinas’s argument is not only consistent with modern science, but actually confirmed by the history of science, from classical mechanics through 19th century thermodynamics to contemporary cosmology.
The first part of the book considers Aquinas’s argument in its historical context, exploring the key principles that everything in motion is moved by something else and that an infinite regress of causes is impossible. The structure of the First Way is analyzed and the argument is connected both with Aquinas’s Third Way—a new interpretation of which is also proposed—and Aquinas’s second proof from motion in the Summa contra Gentiles. To complete the account of what natural philosophy—prior to metaphysics—can demonstrate about God, a chapter on Aquinas’s teleological argument (the Fifth Way) is also included.
The second part of the book tracks the history of modern science from Copernicus to today, showing how Aquinas’s argument fared at each major turn. The first chapter shows how Newton’s understanding of inertia and conservation of momentum supports the idea that motion cannot continue forever without God’s causality, and integrates a modern understanding of inertia and gravity with the principles of Thomistic natural philosophy. The second chapter considers the first and second laws of thermodynamics, showing how they too support Aquinas’s contention that motion cannot continue forever without God’s causality. This chapter also discusses statistical mechanics and contemporary cosmology, demonstrating that science continues to support Aquinas’s unmoved mover argument. The final chapter turns to modern biology as well as cosmological fine-tuning to show that modern science also continues to support Aquinas’s teleological argument. The result is not only a satisfying defense of Aquinas’s natural philosophical proofs for God’s existence, but a primer on the broader project of integrating Thomistic natural philosophy with modern science.
"Daniel Shields presents a careful and thorough treatment of a variety of difficult scientific topics. He takes a generally historical approach to each, describing the development of the disciplines with an eye to deeper philosophical questions that the scientific developments brought up for those scientists. Shields then provides a Thomistic reading of these topics trying to see them in light of and in continuity with Thomistic Natural philosophy. His contribution will hopefully spur deeper reflection and discussion on these difficult questions."~Thomas Davenport, OP, Pontifical University of St. Thomas Aquinas, Rome
" Nature & Nature's God is a landmark piece of scholarship, simultaneously making significant original contributions to the historical literature on Aquinas, contemporary Scholastic philosophy of nature, and analytic philosophy of religion. Shields convincingly argues that longstanding and widespread objections against the First Way are based on misconceptions of the text, and/or misconceptions of relevant data from modern physics. If you thought there was nothing new to be said about Aquinas' natural theology, this superb monograph will thoroughly disabuse you of that notion."~Travis Dumsday, Concordia University of Edmonton
"Daniel Shields has written the most important book on Aquinas’s First Way to be written in decades. Shields rightly avoids the temptation of interpreting the First Way proof as simply metaphysical, a temptation that so many recent commentators have succumbed to, thereby making the First Way into merely a version of one or more of the other four ways or of the argument in De Ente et Essentia. Instead, Shields insists on taking seriously the focus on motion (change), locating the argument within Thomas’s philosophy of nature. Ironically, it is precisely by relating the argument to the details of Aristotle’s actual physics that Shields succeeds in making the argument relevant and compelling in modern terms, since the relevant features of Aristotle’s theory have counterparts in modern science, especially in the Second Law of Thermodynamics. Shields also avoids the error of claiming that the argument proves more than Thomas himself believed. He shows exactly how Thomas proposed to build on the First Way to demonstrate God’s central attributes, including His pure actuality and necessity. Shields shows that his interpretation avoids the standard objections, including those of Scotus, David Hume, Paul Edwards, and Anthony Kenny"~Robert C. Koons, University of Texas at Austin