In response to my post on my readerly annotations, my friend Adam Roberts writes: 

I buy a lot of second-hand books, and previous owners' annotations are almost always a mere irritation. But then I think of Coleridge. From before he settled at Highgate, but very much once he had settled there, his marginalia were specifically, particularly prized. People would lend him books, sometimes very rare and very valuable books, specifically in the hope that he would annotate them, which he did so far as I can see as automatically as a dog pees on a lamppost, simply because it was what he did. And then the people who had loaned him these books would retrieve them from the Gillmans' house with glee. STC died 1834: the first publication of his marginalia was 1836, and magazines like Blackwoods continued to print examples of them throughout the century. By far the most expensive-to-produce element in the Princeton/Bollinger Collected Coleridge set are the five volumes of Marginalia, partly because each is 1000 pages long, but also because the marginalia are printed in a different colour font to the text being annotated, and the volumes come with lavish photos of representative STC pages.

The thing that strikes me about this (speaking as somehow who's read a lot of it) is that the marginalia themselves are, probably, per proportion, something like 20:80, interesting/incisive:blather. So what was the appeal? Some must have been the same that inspired generations of autograph hunters ... and I wonder if that's a hobby that has died out in the digital age? But some of it must have been the way owning a book that Coleridge had annotated brought you closer to the idea of Coleridge himself reading a book. STC was a great writer (obviously you'd expect me to say so) but he's perhaps an even greater reader, and there's value, as you put it, in the sense that by reading STC's marginalia you are as it were peering over STC's shoulder as he reads. 

I think this is a fascinating comment, and, because I have work facing me that I want to put off, I shall now expand on it. 

I’ve just read David Marno’s fine book Death Be Not Proud: The Art of Holy Attention, which is largely about John Donne but also about what people in the seventeenth century thought attention is. Marno points out that philosophers like Descartes and Malebranche talk about attention a good deal, see it as essential to the task of philosophy, but also never define it. They don’t bother to do so, Marno claims, because everyone already understood attention through its religious contexts, its centrality to Christian prayer. Such philosophers thus secularized the act (or faculty) of attention; and as those religious contexts moved from the cultural center to its margins, attention eventually had to be defined, a project still ongoing today. 

Marno further argues — or rather, I guess, implies; I am somewhat overstating his case here — that when Donne’s poetry was rediscovered in the early twentieth century and became greatly celebrated (most famously by T. S. Eliot), the focus on “holy attention” in his sacred poems became matters of scholarly interest. Critics like I. A. Richards continued the work of secularizing attention by seeing the challenge of attentiveness that Donne describes as a challenge for 20th-century readers also. As Donne strove to attend to Christ on the Cross, so Richard’s students strive to attend to Donne’s poetry. Marno notes that Richards isn’t at all interested in the Christian context of Donne’s meditations, and so, rather than suggesting that his students learn something about either Catholic or Protestant devotional endeavors, he points them towards Confucian practices. 

What I want to suggest here is that Coleridge is a kind of bridge spanning the 17th-century and the 20th-century accounts of attentiveness. He is, for his contemporaries, a kind of icon of holy attention — but the holiness resides not in the objects of his attention (which are typically poetic, historical, and philosophical) but rather in the particular character of his own mental dispositions and practices. Yes, Coleridge had deep theological interests, and those intensified as he grew older, but those who saw him as the ideal reader and wanted to collect the sacred relics of his reading didn’t necessarily share his interests or his beliefs. For them, the holiness was not in the text but in the reader.