Sukhdev Sandhu in The Guardian:
Roland Allen loves notebooks. Why wouldn’t he? He is, after all, a writer. In his new study, delightfully subtitled A History of Thinking on Paper, he declares: “If your business is words, a notebook can be at once your medium – and your mirror.” Paul Valéry was at least as devoted to his notebooks as the symbolist poetry for which he is best known. He awoke early each morning for half a century to write in them, amassing 261 books in total. “Having dedicated those hours to the life of the mind, I earn the right to be stupid for the rest of the day.”
Notebooks in different guises have been around since at least the late 13th century. In Florence they were used as ledgers, spurred the development of double-entry book-keeping, and, not least because they were made of paper rather than more expensive and less stable parchment, were integral to the rise of mercantilism. In the form of sketch books they allowed artists to depict their surroundings repeatedly and develop more realistic techniques.
More here.