Dan Phillips from Team Pyro has raised an important and difficult question regarding the origin of the so-called five solas of the Reformation (a somewhat unusal and confusing pluralization of the Latin!). He asks, "Who first used the Sola's? What was the earliest documented use?"
While the truths expressed by the five solas were strongly defended by the Reformers, the formula as we know it most likely has recent origins.
In a review of Terry Johnson's excellent The Case for Traditional Protestantism, Chad B. van Dixhoorn, Research Fellow at Wolfson College, Cambridge University and Director of the Westminster Assembly Project, states the matter provocatively.
The popular delineation of these five solas is not a Reformation idea but a modern one. That is to say, if the Reformers were told to list their core doctrines they might as readily have spoken about salvation by the Holy Spirit alone in the church alone (Scottish Bulletin of Evangelical Theology 23.1 : 119).
Likewise, several months ago at the reformation21 blog, our friends Derek Thomas (in Reformation "solas") and Phil Ryken (in The "Solas" as a Synthesis) gave similar answers.
This still does not answer the question as to who was the first to summarize the teaching of the Reformers in this way (perhaps James M. Boice and R. C. Sproul?). There is need for greater historical, theological reflection on this issue. Surely someone needs to set the record straight! Anyone up for the challange?