Bultmann on history

Bultmann's essay, "Is Exegesis Without Presuppositions Possible?" is a very helpful essay for understanding Bultmann's theology. You might imagine that the title question has one obvious response: "Of course not!", but our man Bulty makes things much more interesting than that! I have been thinking on one point he makes at the beginning:

"Historical method includes the presupposition that history is a unity in the sense of a closed continuum in which individual events are connected by the succession of cause and effect". 

What do you think of that? To me there seems to be so many questionable assumptions even in this one sentence that it made me realise that writing a history needs to appreciate the history of the writing of history! My own work on Paul has not really engaged with history in the sense Bultmann expresses (in some ways, my research was more an exercise in exegesis in terms of epistemology and ontology), and yet I want to develop the skills of a historian in potential later work relating Pauline Christology to "the historical Jesus". Collingwood here I come? I might just stick with John Burrow's A History of Histories for now...