"The contents of his envelopes"

At the TLS, David Wootton has a thought-provoking piece on Keith Thomas's book on happiness. Some interesting reflections at the end on the shape of the field of British history of the early modern period as it has changed over the last forty years, but the bit I liked best was this:

The texture of the book reflects the author’s method of working. He reads voraciously and indiscriminately (“I try to read everything”), and copies out telling phrases he notes onto pads of paper. Thus when Thomas tells us that John Donne, in one of his sermons, says that “work” is “a word that implies difficulty, and pain, and labour, and is accompanied with some loathness, with some colluctation [ie, struggling]” it is a reasonable guess that he has come across this quotation by the elementary procedure of reading all twelve volumes of Donne’s sermons. It so happens that I too have read all Donne’s sermons, but I read them in order to understand Donne’s theology. I find it hard to imagine what it would be like to read them for Donne’s passing references to daily life, to courtship and children’s toys, to holidays and labour, to sickness and health – to read them, as it were, constantly against the grain. And harder still to imagine what it would be like to realize that hundreds and hundreds of such volumes would need to be read before one could construct a paragraph on, say, the ostentations of the wealthy. But that is how Thomas has worked, and the resulting pages of notes are then cut up and put in envelopes with labels such as “Clothes” or “Dirt”. When he wants to write, he empties out an envelope and begins to arrange the quotations, clipping them into place on sheets of paper.