I closed my previous post by suggesting that it is appropriate to refer to all stages of salvaton history as dispensations. But, the question is raised, what are those stages?
My answer is this: it's not so important to develop a set of dispensations as it is to read Scripture dispensationally. You see, God plays His story out progressively, both in the revelation He gives to humanity and in the way He interacts with humanity. Some of the progressions He makes are major turning points in salvation history (such as the death of Christ), some are expansions of promises (such as the Abrahamic covenant), some are tweaks in the way humans interact with each other (such as capitol punishment after the flood), etc.
If we viewed any stage as a dispensation which is distinguishable from what was before it, we'd see dispensations everywhere! If we limited the dispensations to those stages which are also distinguishable from what comes after them (in the sense that something is detracted from them), we might see very few dispensations.
So, it seems to me that we ought to view salvation history as a progressive continuum. At some places along that continuum, a promise or stipulation is added. At some places, a covenant arrangement is detracted (the fulfillment of the Mosaic Covenant, etc.). The important thing is that we view any given portion of Scripture in its preceding salvation-historical context. So, when reading our Bibles, we ask, "what was revealed by this point?" or, "what stipulations were given by this point?" etc. You see, this is not so much developing a set of dispensations as it is reading Scripture dispensationally.
But what is the relationship between dispensations and covenants? Well, that's a tough question to answer because because we're dealing with both little-d dispensations and capitol-D Dispensations, and because we're dealing with both little-c covenants and capitol-C Covenants. Consider the period between the flood and the Abrahamic covenant. People could now eat meat, and capitol punishment could now be practiced. This wasn't a major turning point in salvation history in the same sense that the giving of Mosaic Law was. But, it was distinguishable from what came before it. Depending on how broadly you want to define “dispensation” and “covenant,” you could apply both terms to this. Of course, a big-D Dispensation and big-C Covenant would be more like the Mosaic era.
Either way, we might say that a covenant is the arrangement communicatively, and a dispensation is the arrangement practically.
So, what is the best way to structure salvation history? I tend to think that there is no right or wrong answer. Dispensationalists recognize the importance of covenants, and covenantalists acknowledge the existence of dispensations. Moreover, there would be nothing inherently inconsistent about the inclusion of overarching “theological covenants” into dispensationalism.
In my opinion, there is value to “overlaying” multiple perspectives on salvation history. We could take a really wide angle snap-shot, and see salvation history in terms of the covenants of Works and Grace. Or, we could zoom in closer and see salvation history in terms of progressive covenants, dispensations, or promises. The best structuring of salvation history is multi-perspectival and includes all of these.