Book Review: Andrew Walker’s “Faithful Reason: Natural Law Ethics for God’s Glory and Our Good”

Editor’s Note: The following book review appears in the Fall 2024 issue of Eikon.

Andrew Walker. Faithful Reason: Natural Law Ethics for God’s Glory and Our Good. B&H Academic, 2024.

A Morally Ordered Oughtness to the World

There is a moral oughtness to the world. That is, the universe evidences moral design, and humanity should operate in accordance with this design. To deny moral order is to live irrationally and to plunge individually and societally into ruin.

This moral order is divinely imposed and not a social construct. A transcendent being has created this world to operate in ways that are consistent with his being and result in human flourishing. Furthermore, this divinely imposed order is knowable via reason, even to human persons whose reason is marred by the noetic effects of sin. Rational, fallen men and women can truly know what is right and wrong, though those same beings “can err by way of judgment and application” (10).

Given that God has ordered the universe and implanted in humanity “the ability to know right from wrong [i.e. moral order]” (2), human beings should live in light of that moral order for society’s good and God’s glory. As Andrew Walker defines natural law, there is a “God-ordained, God-upheld system of moral order engraved upon an image-bearer’s conscience…” that we can know through reason and that “directs rational creatures to know what actions to do and what goods to fulfill [and] … what actions to avoid and vices to shun” (28).

For Walker, the existence of natural law “gives us rational, coherent ways of understanding the structure of God’s creation order” (42). Thus, our biblically informed and held convictions “can be rationally articulated in ways that better benefit human flourishing and the common good” (42). This sense of oughtness (or transcendent moral order) that is engraved on the heart of every person gives a “common moral grammar” (175) to believer and unbeliever alike. In terms of ethics, Christians can and should “couch their arguments” (175) for right and wrong in ways that rational, though supposedly non-religious, persons can grasp.

Development/Structure/Flow

Walker patiently introduces, defines, describes, and clarifies the subject of natural law for the reader. He moves from worldview discussions to definitions and philosophical, biblical, and theological foundations for natural law. His formal philosophical definition of natural law and natural law theory is as follows:

The moral theory that a divinely ordered and self-evident universal moral order exists that human reason can, in principle, grasp as intellectually knowable, which serves to direct our behavior toward morally choiceworthy goods and away from moral evils. This comprehension of the moral order and its basic, non-instrumental goods defines and identifies which actions are reasonable and worth pursuing — even apart from an immediate appeal to divine revelation — by achieving the purposes or goals necessary to human nature’s fulfillment and society’s proper coordination. Natural law is thus action-guiding and action-explaining. It explains what we ought to do and why we ought to do it by providing reasons for action and reasons for restraint (75–76).

As noted, natural law refers to a divine order that is universal and knowable via human reason. As we grasp natural law, we discern how to live and how to offer intelligible reasons for action and restraint. The foundations for this perspective are laid in four chapters. Two introduce philosophical foundations for natural law. In terms of origin, the natural law exists because there is “an eternal being ordering it into existence” (133). Though the unbeliever may not know the source of natural law, natural law is because “God decrees” it (135). And natural law is knowable or per se nota (self-evident) and has both content and utility. There are rules, norms, and principles for moral action that are useful, not merely for apologetics but also because the natural law gives “explanation of the world’s affairs and our place as rational creatures within it” (175). 

Walker then moves to biblical and theological foundations of natural law, showing that Scripture assumes it and makes good theological sense. Scripture’s “account of creation” is “orderly and intelligible” (181), as when Psalm 19 declares the heavens declare the glory of God and the skies his handiwork. Romans 1, the “natural theology lodestar,” tells the reader that there are “plain” realities that demand a right response (Rom 1:19). And Paul’s stress that even pagans would not tolerate what the Corinthians are tolerating assumes “some knowledge of universal moral laws governing proper sexual relations” (195). Walker writes, “To invoke the natural law, then, is not to impose an alien and external morality on an interlocutor but to draw out a morality that Scripture considers present from within a person’s knowledge of the world” (190). 

Next, Walker supplies ten theological axioms in reference to the natural law, considering it from two horizons. From above, the natural order simply is because God has imposed it (so Rom 1). From below, humans recognize this order through reason and conscience. While sin warps the ability to grasp rightly the moral design of God’s universe, depravity does not entirely remove the ability to grasp the moral design all around us. “That we can name our sin and injustices evidences how glimmers of the natural law still break through the darkness of the human heart” (216) — what John Calvin in the sixteenth century called the sensus divinitatis. The mission of the church to preach the gospel of salvation ever remains central; nevertheless, Christians in all times and places must also call the world to live in light of “the creation order it is hellbent to reject” (238).

Having laid the necessary foundations (philosophical, biblical, and theological) for the natural law, Walker now applies this framework “to a host of issues where the natural law offers definitive clarity” (245). Building off Thomas Aquinas, Walker leans into the taxonomy of (1) Life, (2) Relations, and (3) Order to show how the natural law is brought to bear on volatile issues of our day (e.g. abortion, same-sex marriage, politics).

Important Contributions

There are several important contributions this study makes to the field of ethics and natural law. First, Walker’s definition and descriptions are clear, careful, consistent, and faithful. Within the first six pages, he describes natural law and how it works in plain language. By page twenty-eight, he offers a careful and detailed definition, which he then repeatedly unpacks in his book. 

Second, Walker keeps Jesus Christ central in the place of ethics, so that he speaks even of a “Christotelic natural law” (82). While many limit discussions of Jesus to the way he redeems humanity for a future existence in the new heavens and new earth, Walker rightly stresses how Christ is vital for how we live in the present evil age, too: “The reason we understand morally intelligible propositions such as ‘it is evil to torture babies,’ is because Jesus Christ has structured the universe and our awareness of this moral reality to be what it is” (86). Even further, “It is in Jesus Christ where we see the embodiment of just action mediated by love. It is through our obedience to Christ that we understand what ‘good’ in both the natural and heavenly domains means” (364). Though this moral order may be grasped through human reason, Walker in no way severs the need for Jesus in our ethical thinking.

Specifically, natural law theorists like Walker have not forgotten the doctrine of depravity. He states, “No natural law proponent that [he is] aware of discounts the impact of sin on human reason” (374). Sin mars reason but does not eradicate it: “While humanity may be unable to account for its own moral intuitions, the fact that longings for justice and meaning persist testifies to the natural law” (376). Humans can err in their judgements, and we can be ever grateful that God has given us a more sure word (i.e. the Bible) that clarifies and heightens what we find in the natural law.

I used to consider natural law arguments only to benefit apologetics, defending Christian ethical claims within the public square and answering objections and questions. Yet Walker showed me that, before moral apologetics is outward-facing, it must be “inward-facing as a method of ethical catechesis” (34) so as to allow us “to be apologists for the moral superiority and eminent humaneness of Christian ethics” (35). Walker, therefore, strengthens the Christian church by showing us that we are “not eccentric cultists or crazed fideists” for believing culturally taboo realities (e.g. men are men and women are women) (35). Indeed, “the burden of [his] argument in this book is to demonstrate the need for Christians to better grasp the natural law as a corollary to their discipleship. Christians need more rigorous instruction on the integrity of Cristian ethics if there is to be any possibility of a future public witness” (36).In the end, we should recognize that the order of this world is stunning and should result in praising the one who established the order. When through reason I perceive an oughtness to the world, I know from whence that oughtness comes. God has imposed a moral order to the universe. As Christians, we not merely call people to be saved from sin and death through the cross of Jesus Christ, but must also call people to live in accord with the order that God and his Christ have imposed on this world for their good and God’s glory.