When the user stores his thoughts in his own filing cabinet, these thoughts are no longer his own but those of his filing cabinet. In turn, the machine that gathers and reproduces excerpts is, and remains, a ‘black box’. It is not simply another Ego for enacting a user’s soliloquy but a true Alter Ego with whom the user communicates. Additionally, when the machine is started, the user does not simply refresh his memory; the filing cabinet actually speaks. To achieve this practical outcome, the card index must be provided with a ‘life of its own’ (Eigenleben) which should be as independent of the life of its educator as possible.30 In this sense, the card index functions as a ‘secondary memory’ in Stübel’s terms. This result raises some questions which justify the present article. Is there a socio-structural reason why such an improbability became possible? Is there a trend, in early and late modern society, toward an externalization and technologizing of social memory? And what insight can we gain into intellectual history?