In 1945 Vannevar Bush proposed a machine that acted as a "supplement" to memory and met the particular information needs of its user. Because this "memex" recorded "trails" of selected documents, it has been seen as a precursor to hypertext. However, this paper considers Bush in relation to earlier concerns about memory and information, via the ideas of Robert Hooke and John Locke. Whereas Bush modeled the memex on the associative processes of natural memory, Hooke and Locke concluded that an external archive had to allow collective reason to overcome the limits of individual memory, including its tendency to freeze and repeat patterns of ideas. Moreover, they envisaged an institutional archive rather than one controlled by the interests and mental associations of an individual. From this early modern perspective, Bush's memex appears as a personal device for managing information that incorporates assumptions inimical to the strategies required for scientific analysis.