The Light That Binds: A Study in Thomas Aquinas’s Metaphysics of Natural Law by Stephen L. Brock (review)

Although the subject of this superb book is Thomas’s doctrine of natural law, it will greatly profit those interested in any area of his thought. The long history of Thomism has passed through phases, and Stephen Brock’s book can serve to mark the end of the “neoscholastic” period, which lasted most of the twentieth century. Neoscholastics decided to counter the onslaught of the nineteenth-century rationalists against the Roman Church by meeting them on their own ground, separating Thomas’s philosophy from his theology. The motto of this tactic can be seen in the English subtitle of the Vatican II document Gaudium et spes, “The Church in the Modern World.” Unfortunately, as Catholics reached out to the “modern” world, it became “postmodern.”

The era’s two most renowned Catholic philosophers, however, Jacques Maritain and Etienne Gilson, eschewed the neoscholastic path. When Gilson asked the positivist Lucien Levy-Bruhl to direct his dissertation, he was told he “must undertake something positive, speculative philosophy just wouldn’t do.” Gilson said he would “do the history of philosophy. That’s positive enough, isn’t it?” And Jacques Maritain’s The Degrees of Knowledge ranges from ordinary experience of the physical world, through modern science, natural philosophy, metaphysics, and theology, all the way to mystical experience.

Brock’s book began life as a dissertation (xiii) structured in response to neoscholastic views on Thomas’s natural law. Far from dating it, this structure is what makes this book so important now. He begins by organizing neoscholastic efforts (chap. 1), which opens up his lengthy response (chaps. 2–7), a detailed analysis of Thomas’s own texts and arguments, the only sure way to capture Thomas’s genuine thought, combined with clear-headed critique of selected neoscholastics. So Brock offers not just a superior interpretation of Thomas, but also a tutorial on how to arrive at it.

Brock first divides neoscholastic views into two groups: (I) a natural law completely autonomous from God and eternal law; and (II) natural law in some way connected to God. Then he subdivides each, producing four types.

I.A. “Natural Law as Law in a Qualified Sense”: The neoscholastic view was initiated by Odon Lottin, O.S.B., who demoted natural law to the status of an “intrinsic morality,” a purely rational ethics which is not law in the full sense, for it lacks a strong sense of “obligation” (debitum), command, and sanction. Germain Grisez followed him, and Grisez’s collaborator, John Finnis, said natural law is “only analogically law.”

I.B. “Self-Standing Law”: Natural law, considered in itself, is law in the full sense of the word, so much so that Frederick Copleston, S.J., said “it is the human reason which is the proximate or immediate promulgator of the natural moral law.” Consequently, “we can speak of a certain autonomy of the practical reason.”

II.A. “A Not Quite Natural Law”: On this view, in order for natural law truly to be law it must involve God. For Ernest Fortin and Harry Jaffa, however, this connection cannot be established rationally; so rational natural law fails.

II.B. “Natural Law as a Natural Divine Law”: To be law, natural law needs some necessary connection with God; but proponents split about whether we can or need to know this connection. Francisco Suarez, S.J., said that this connection is not self-evident, like the principles of the natural law themselves, but it is proven rationally: “The natural law existing in us is a sign of some will of God. . . . Therefore natural law includes this will of God”; a view also embraced by Lawrence Dewan, O.P. Others, however, hold that while the reality of natural law in us depends upon God, to be sure, it can function without our knowing this. Peter Geach says...