This is largely inspired from a couple of posts over at Daniel's Neothelogue. One of his textbooks presents a method of determining Christian orthodoxy which uses the following definition of "Tradition": the consensus beliefs held in common by the early church fathers and the Reformers of the sixteenth century as expressed in common by the ecumenical creeds and Reformation confessions of faith.
On the whole, this is a pretty good definition of how Protestantism understands tradition. It is probably only absent a caveat about it being subject to Scripture and a good definition of "early fathers" (the cut-off date for acceptability could have massive implications for our theology). But the more I think about this, the more I think that this is actually an impossibility. There is no way to reconcile Patristic thought with the ideals of the Reformation. I say this as someone not intimately familiar with either, but I probably know just enough to be dangerous - so if I err in some regard, please correct me. And my full thoughts on this will probably take a few posts to explore, so bear with me.
Now, it may be possible to reconcile Reformation thought (RT) with particular Fathers, or Patristic thought (PT) with a specific Reformer. For instance, I know that Luther did not start out with the intention of splitting from the Roman Catholic Church, only correcting it. It is possible that within the time-frame he was still seeking reform from within the Church, his thinking was well in-line with PT. I have not read much Luther, so I honestly cannot say. And, of course, many of the Calvinists I have come across tend to look back to Augustine as support the antiquity of their theology, but if Augustine actually does agree with Calvinism (a point on which I remain skeptical), I dare say that it is an aberration in PT. If time permits, I will try to get into some direct comparisons between some Patristic authors and Reformation confessions to flesh this point out.
So why is a consensus impossible to achieve between PT and RT? Quite simply, in answering the question of orthodoxy, they are guided by 2 principles that are alien and antithetical to each other. In the Patristic witness, what is the norm and source of orthodoxy? The Church as she lives in faithful adherence to the Apostolic Tradition, which contains the Bible, and the Ecumenical Councils. An individual believer is called to obediently participate in that life, submitting to the Church in all areas of dogma & theology. In the Reformation ideal, what is the norm and source of orthodoxy? The Bible (sola Scriptura), guided by reason and tradition (though what exactly this tradition is may be a matter of some dispute). The individual believer is called to evaluate all that the church and her leaders say in light of the Bible and come to their own decision about whether it accords with Scripture. Thus, private judgment is able to trump everything - as long as it makes sense to the individual, no amount of tradition or the reasoning of others has the authority to declare a doctrine or belief incorrect.
It is this principle that is so foreign to PT. The ideal of private judgment effectively raises the individual above the Church, but it is clear in the Fathers that it is the Church that holds sway. I will develop this further, but this, in a nutshell, is why there can be no consensus between PT and RT.