Book Review: Faith in the Age of Reason by Jonathan Hill

Faith in the Age of Reason by Jonathan Hill is a concise history of the Enlightenment from Galileo to Kant. The goal of the book is to acquaint the reader with the central ideas and figures of the Enlightenment to show the progression of ideas and philosophies between the mid-seventeenth century and the year 1800. This short chronology includes many vignettes of important historical figures, their thoughts, and accomplishments.

The book begins by describing the philosophical and religious thought systems that preceded the Enlightenment: the Middle Ages, the Renaissance, and the Reformation. Most notably, the Middle Ages was rooted in the notion of the authority of the church. Later, through the Reformation and the Enlightenment, scripture and science challenged this authority. The “Age of Reason,” a term used synonymously with “Enlightenment,” would bring an end to the idea of a unified body of knowledge among the various disciplines.

“The most cherished ideal of the Age of Reason was reason itself: the human capacity, by means of investigation rather than by relying on external authority, to understand.”1 And so the author continues by offering a historical overview of the progression of the Enlightenment from its inception, and includes brief descriptions of the key thinkers. After this overview, the book gives a more detailed look at some of the broader themes of the Age of Reason.

Next we follow the progression of scientific thought, as the belief that the world was fundamentally comprehensible replaced previous ideas of mystery and magic. From Galileo’s and Halley’s discoveries in astronomy, through Newton’s breakthroughs and his Pricipia, to further progression in medicine and biology, the author shows how the fundamental changes in the view of the world affected the leaps forward in the hard disciplines of the sciences.

After a discussion of scientific progress, Hill moves on to illustrate the changes that occurred in the church and in philosophy. Various shifts from the Reformation caused a period of confessionalism and scholasticism in which doctrines were more clearly defined and clarified. Within philosophy, the author points out that there was no clear distinction made in the Enlightenment mind between philosophy and science. The word “scientist” had not been invented yet. These new movements in science had a direct influence on science and religion. Among the influential were such thinkers as Descartes, Spinoza, Locke, Leibniz, and Berkeley.

Hill proceeds to discuss some of the deeper elements of Enlightenment thought, and their shifts from earlier medieval paradigms. Of note would be the shift from the idea of the essential agreement between faith and reason. The Middle Age system of thought saw faith “perfecting” reason, as displayed in the thought of Thomas Aquinas. The medieval thinkers had the idea that, “although all the different branches of knowledge form a coherent whole, it can still be divided into different disciplines, each of which has its own method of inquiry ... the new philosophy was breaking this understanding of human knowledge apart.”2

The author concludes the book after a few chapters discussing the development of various forms of deism in England, France, and America. Deism becomes the “half-way house” between Christianity and atheism. Atheism was an extremely new way of thinking that was seeded from the deistic fruits of the Enlightenment.

Faith in the Age of Reason is a good resource book, littered with quotes, illustrations, and historical insets. As a basic primer on the progression of philosophical, scientific, and religious trends through the Enlightenment, this book provides a great introduction with many useful insights.

1 Jonathan Hill, Faith in the Age of Reason (Downers Grove, IL: InterVarsity Press, 2004), p. 26.
2 Ibid., p. 117.