primary sources 1.0

We’ve all heard the analogy of many pianos all tuned to a single source. As a by-product all the instruments are in tune one with another. I like this analogy, because I know the devastating results of tuning any other way. So why do we tune in other ways? Why have we thought it sufficient to tune each piano to the one beside it, so that any error along the way gets compounded in each subsequent instrument?
A popular way to tune the guitar is by using the harmonic at the 5th fret as the pitch by which to tune the harmonic at the 7th on the next higher string. This method is acoustically perfect and easy to hear, but our tuning system is not based on an acoustically perfect model. We use a system called equal temperament, meaning that most notes are adjusted a bit out-of-tune, so that we end up with equal intervals across the scale. By tuning the guitar in the method described above, the first string tuned will be 2 cents off from equal tempered tuning. Each string will be 2 cents off from the preceding string, but 4 cents off from the one before that. Each string adds its 2 cent error to the already existing difference between the preceding strings.
Maybe analogies are not what are needed here. Shouldn’t we be able to look back and see that as we’ve tuned each of our strings to the immediately preceding string, that we’ve unquestioningly depended upon the accuracy of that string – so much so, that we will cite it’s frequency as proof that we’re in tune. At each step along the way, each tuning uses as its argument, the presumed accuracy of the ones before it, but it seems not to be noticed that they are all not tuned to one another, the errors seem to be random, and the discordant discrepancies seem to be ignored.
In Christendom, we have canonized commentaries and interpretations, mandates, resolutions, etc., as the basis of our doctrine as if they were to be included in the inerrant, God-breathed canon of Holy Scripture. We are so much quicker to quote Calvin or Luther, or Darby than we are to grapple over the primary sources of the Gospel. We verbally live and breathe by the doctrine of sola scriptura, but in practice, opt for decisions, resolutions, and interpretations made by historical religious figures. A way of discipleship that they, themselves were trying to reform.