Having now read (or re-read) most of Grafton's book on The Footnote. A Curious History, I have three initial reactions:
(i) I do not really understand what Zerby means when he claims that he entirely disapproves of "what happened to the footnote in Ranke's hand" (90n), while Grafton approves of it. Grafton is not only highly critical of Ranke and his use of footnotes, but also of the power of footnotes and "scientific history" in general. Thus he claims that "Ranke, the founding father of the modern historian's craft, practiced it with no more discipline than his professional grandchildren and great-grandchildren ... he used a salt shaker to add references to an already completed stew. This seems to have been Ranke's consistent practice" (65). Hardly a ringing endorsement. In general, he observes that "to the inexpert, footnotes look like deep root systems, solid and fixed; to the connoisseur, however, they reveal themselves as anthills, swarming with constructive and combative activity" (9). Or: "Footnotes guarantee nothing, in themselves ... Yet footnotes form an indispensable if messy part of that indispensable, messy mixture of art and science: modern history" (235). It's hard (for me) to disagree with the last sentiment.
(ii) Grafton's book is hardly a history of "the" footnote. It is a history of the footnote as used by historians (with very short detours into other disciplines and genres). The role of footnotes in theology, philosophy, which, as I would argue, is at least as important, is not really treated. (One thing that makes Zerby's book interesting is that he also looks at literature and at the difficulties printers had with them from the beginning.)
(iii) The name of the philosopher "Kant" occurs once in the Index. He is discussed on p. 108, though "discussion" is probably not the proper word for the way he is treated: "Hegel wished to distance himself from Kant, the most oppressive and challenging of his predecessors, who had made masterly use of footnotes to give material form to his inner ambiguities. Kant, as Wolfert von Rahden has shown, deliberately confined all suggestions that reason might have had a historical origin or might undergo a further development to the murky region below the superstructure of the text." Well, "has shown" is always an occasion for doubt—at least for me. And "has shown that X deliberately did y" leads me to ask "Really, and how?" In this particular case, there are even bigger problems. Even though the accusation is old, going back to Johann Georg Hamann and his Metacritique, there is also a chapter in the Critique of Pure Reason entitled "The History of Pure Reason," which Kant strategically placed at the very end of his work. Since it mentions Democritus, Plato, Aristotle, Epicurus, Locke, Leibniz, Wolff, and Hume by name, and alludes to a host of others as relevant for the history of reason, I beg to differ for that reason alone. At the very least, this shows that the universal claim about "all suggestions" is just false. But I will have to take a closer look at the book by Wolfert von Rahden, which is the only thing cited in support of this claim—something that in philosophy (or perhaps better: in the history of philosophy) would hardly be sufficient.
1. An example of why one should never rely on a secondary source alone?
2. See also point (ii).