This was posted by GospelCrazy on WonderCafe (Tue, Nov 14/06 05:31 pm) and I asked if I could quote him. He says it is not the best description, but off the top of the head in a nutshell summary. I find it helpful to know that it is an old tradition that was not invented by the United Church (contrary to some opinions stated on the site) but a well-thought out biblical approach.
The United Church does come from a reformed tradition, but it is also heavily influenced by John Wesley's "evangelical" methodism. Wesley was concerned with finding a way of being Christian that would speak to his people in his time and place, and he scoured every bit of tradtion he could get his hands on, including church fathers, Moravian theology, and parts of the Bible that were largely overlooked by the church leaders of his time. His criteria for it were: does it have authentic Christian background? and is it useful? A sort of pragmatic traditionalism.
Wesley taught four bases for theological reflection, so Sola Scriptura certainly does not apply to him. I have seen a number of UCC theologs referring to the four bases ("The Wesleyan Quadrilateral") in various threads on this forum.
The Wesleyan Quadrilateral is Scripture, Tradition, Reason, and Experience. Various Methodist theologians have arranged the significance of these in various ways, but I believe (I stand to be corrected by those who are greater Wesley authorities than I) that he would have privileged Reason above the other three as the filter through which all else becomes meaningful.
I think this element of Wesley's teaching sheds a great deal of light on some of the conflicts that are taking place in this online community right now, as it is lived out in the lives of many UCC ministers and scholars and brings them into conflict with those who have a more reformed "Sola Scriptura" position.
I hope everything I have said is reasonably true to Wesley's actual teachings; I don't have my books with me. And I hope that this is helpful to you, Deo_gratias, in your attempts to better understand the United Church of Canada context.