In his “Méthode nouvelle,” an anonymous article in the Bibliothèque universelle of 1686, John Locke described his way of collecting excerpts in notebooks and retrieving relevant entries. The well‐known practice of entering textual passages in commonplace books sits uneasily with Locke's criticism of received opinion and authority. Is it possible that he used any of these notes to think with? I suggest that the conditions for this were provided by Locke's interactions with some of his notes, including those which recorded observations, testimonies and experiments. As well as labelling excerpts and other notes with topical Titles, Locke sometimes added precise bibliographical citations, transferred material across notebooks, interpolated his own signed reflections and queries, and (eventually) dated entries.