By What Authority? an Evangelical Discovers Catholic Tradition Book

Mark Shea used to think that the sole criterion for religious truth was to hold anything being disputed up to the question, "Is this Biblical?" In this intellectual memoir, he describes how and why his criterion changed over time, so that the key question for him eventually became, "Is this Apostolic?"

Shea writes with an enthusiasm that I liked very much, seizing late in the narrative on metaphors to say that "Tradition is the lens that focuses the light of Scripture," and then "Scripture and Tradition are the hydrogen and oxygen that fuse to form living water." Both images are instructive, and both help to make the important and utterly Catholic point that "extra-biblical" belief is not necessarily "anti-biblical" belief.

Shea did his homework, as citations from church fathers like Clement of Rome (circa 100) and Basil the Great (d. 379) show. He brings the reader around with him to the realization that what separates Sacred Tradition from the folkways that Scripture warns us about is a twofold test, pithily described as the "Roots and Fruits" standard. That coinage may not be original to him, yet Shea uses it to wonderful effect.

I almost gave this book five stars, but an overview of extra-biblical beliefs that most Evangelical Christians regard as non-negotiable seems muddled. The book also shows its age by using the unintentionally comical heresies of John Dominic "Jesus Seminar" Crossan and John Shelby Spong as its jumping off points. Both men were more influential 15 years ago than they are today, although the thinking to which they are beholden is still with us, and Shea's dismantling of their best-known heresies remains entertaining.

Criticisms aside, "By What Authority" is a quick read that I warmly recommend to any Christian with an interest in apologetics or the ongoing dialog between Catholics and Protestants.