The Notebook of the Authorship Investigation (EA-NOTEBOOK-01) is the working record of a multi-month investigation into the relation between the Platonic and Aristotelian corpora, kept append-forward across fifty-four rounds and three framings, with nothing erased. It is not a paper and makes no argument in its own voice: it records readings, measurements, retractions and voids in the order they occurred, so that every number and reading in the derived papers can be traced to the round and section that produced it, with any refutation attached where one was made. The rounds run from the snub locus and its refutation by its own base rate (R1–R2), through the fragmentation and symbolon structure (R9), the six-function transmission apparatus and its rival specifications (R12–R13), the object-conditioning parity and its correction (R18–R19), the school rival measured three ways and then voided as an operator test (R24, R28–R30), the lexical battery and every control that killed it (R31–R39), the attestation audit and the control that went against it (R40–R43), the comedy-and-tragedy structure (R45), the coverage anomaly (R47), the ladder (R50), the arithmetic of the four propositions (R51) and the comic layer of the accusation (R54). Its discipline is stated in its own pages: the ordinary reading first and in full, every result travelling with its limit, and a number not in the file did not happen. Companions are the measurement register (EA-AUTHORSHIP-MEASURES-01), which holds the figures with their conditions, and the frozen pre-registration ledger, which holds what was fixed before each test. The notebook is deposited as the maximal form of the investigation's record; a later correction to Round 54 §245 — the Clouds relabelling result, found to be a counting artifact — is to be appended as a subsequent round rather than edited in, which is what append-forward means.