Long before there was the Internet, there was the commonplace book — a creative and intellectual ledger of fragmentary inspirations, which a writer would collect from other books and copy into a notebook, often alongside his or her reflections and riffs. These borrowed ideas are in dialogue with the writer’s own imagination and foment it into original thinking. Over long enough a period of time — years, decades, often a lifetime — the commonplace book, while composed primarily of copied passages, comes to radiate the singular sensibility of its keeper: beliefs are refined, ideas incubated, intellectual fixations fleshed out, and the outlines of a personhood revealed. (Brain Pickings is, in an unshakable sense, a commonplace book.)