Before I dig into the meat of the book, I want to give some preliminary remarks:
(1) This book is not an attack of Charismatic-Pentecostalism, nor is it any kind of hit-piece on Christians who speak in tongues. The tone is extremely scholarly and narrowly restricted to the question of how Christians have understood the gift of tongues, especially in the last three centuries. Those who are looking for a hit-piece on Charismatic Christianity will be disappointed, while those Charismatics who are worried precisely that this is a hit-piece need not be. It offers no arguments against nor critiques of Charismatic Christianity as a spirituality one way or another, choosing instead to stick to an analysis of historical texts and their interpretation.
(2) Since both Catholicism and Protestantism have charismatic subcultures, this book has an ecumenical appeal. It is not a "Catholic" book, per se. In fact, one author is Catholic (Philip Blosser) and the other Protestant (Charles Sullivan). The book has no confessional "angle." It could be read with equal value by a Protestant or a Catholic.
Now, on to the synopsis:
The miracle of tongues as xenolalia is well established in Church history, both within Protestantism and Catholicism. In fact, as Blosser and Sullivan demonstrate, prior to the late 1800s, no theologian anywhere in any Christian confession identified tongues as anything other than xenolalia—the miraculous, intelligible speaking (or hearing) of previously unlearned human languages. From whence, then, did we get the concept of tongues as an incoherent "private" language as denoted by glossolalia?
Here Blosser and Sullivan do some excellent historical sleuthing, tracing the evolution of the idea back through the revivals of Topeka and Azusa Street to the British Irvingite movement and the Second Great Awakening. Modern Pentecostalism grew out of the apocalyptic stew of these various movements, which all shared in common the notion that God was going to "restore" the Church in the "latter days" to more closely resemble the Church of the New Testament. The problem was most mainline Protestant denominations after the Reformation had rejected the continuation of miracles (a position known as Cessationism) in reaction against the multitudinous Catholic miracle stories of the Middle Ages. But the New Testament clearly teaches that miraculous charismata are meant to continue in the Church. The early Proto-Pentecostal movements thus sought to find a way to reintroduce the miraculous into their congregations to mimic the New Testament Church, or at least their vision of it. Hence the advent of modern tongues (beginning with Agnes Ozman, the first person to "speak in tongues" in the contemporary sense in 1901) as a "restoration" of the spiritual gifts to the Church.
With admirable erudition, Blosser and Sullivan document how these early revivals led to a burst of Pentecostal missionary activity. It was believed that the "restoration" of tongues would do away with the need for missionaries to spend years learning foreign languages. Emboldened by the Holy Spirit, Pentecostal missionaries set sail for the distant mission fields of China and India, believing whole-heartedly that they would be able to speak their utterances to foreign peoples who would miraculously understand them. They were shocked and disappointed to find that their utterances were completely unintelligbile—we can only imagine the confusion of a Chinaman or Hindi-speaker at hearing the incoherent utterances of these strange westerners. These experiences were a source of profound disillusionment for early Pentecostals, triggering what Blosser and Sullivan refer to as the "Tongues Missionary Crisis" of 1906-1909.
Volume 2 of Blosser and Sullivan's series (which I have not read yet) chronicles how Christians have viewed tongues throughout history. The forthcoming Volume 3 is exclusively devoted to the tongues of Corinth mentioned in the New Testament, answering the question, "If the tongues of Corinth were not glossolalia, what were they?"
While Blosser and Sullivan's book is critical of contemporary biblical exegesis about tongues, it is not, as I said, critical of Pentecostals themselves and makes no judgment upon their spiritual lives. It is a work of historical theology, exploring the "genealogy" of a theological definition. Speaking in Tongues Volume 1 is an excellent resource for understanding the theological development of this practice which, whatever you think of it, has become so ubiquitous in Christianity today. I highly recommend anyone with an interest in this subject get a copy of Volume 1 and Volume 2.
Incidentally, I sat down with the authors recently and recorded an audio interview with them, which you can listen to on the Unam Sanctam Catholicam YouTube channel (which you should also subscribe to : )